Landscape Trees (part 1): Selection, Planting, Transplanting and Care [audio]
Growing healthy trees starts with choosing the right plant for the right place, and good planting technique. And with adequate care early in the tree’s life, you’ll be well on your way to the shade, blooms, privacy screening, wildlife habitat, or whatever you’re trying to achieve with the new addition to your landscape. In part 1 of this 2 part episode on trees, Greg Jordan, Emma Erler and Nate Bernitz talk about all this and more. Then look for part 2, which will focus on pruning and tree problems and solutions.
- Featured Question: How to transplant established trees?
- Featured Plant: Tamarack (Larix laricina)
- Closing Tip: Transporting Trees from the Nursery
- Planting and Care of Tree Seedlings
- Planting and Mulching Trees and Shrubs
- List of Trees for New Hampshire Landscapes
- Transplanting or Moving Trees and Shrubs in the Landscape
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Transcript by Otter.ai
Nate Bernitz 0:00
Welcome to the Granite State Gardening podcast, a production of the University of New Hampshire Cooperative Extension. This is part one of a two-part episode we're bringing you on tree care, which will cover everything from tree selection to planting to pruning, and tree problems and solutions. Emma also did some really interesting special segments for this episode, so make sure to listen all the way until the end for those. Emma and I were joined by UNH Extension forester, Greg Jordan for this episode, and I really enjoyed learning from both Emma and Greg, and I think you will too. Before we get into today's episode, I want to ask you to do something for us. We have a listener survey that asks a few questions that will help us understand the impact of the podcast on you and to improve it to better meet your needs. As an incentive, because we'd like a lot of responses, we're doing a giveaway. One person who completes the survey will be randomly selected to receive a pair of Felco pruners. Follow the link to the survey in the show notes. And thank you for taking the time. And of course, thank you for listening to the podcast.
Greetings Granite State gardeners. I'm Nate Bernitz, Public Engagement Manager for UNH Extension, joined by horticulturist and UNH Extension field specialist Emma Erler, as well as Greg Jordan - Rockingham county's Natural Resources Specialist, semantically referred to as the Rockingham County forester.
Greg Jordan 1:37
Great. Well, thanks Nate. My name is Greg Jordan. I'm a forestry specialist with UNH Extension. I'm a New Hampshire licensed forester and a New Hampshire certified arborist. I work primarily in Rockingham County, but I work throughout the state. I work with private landowners with landscape issues and trees. I work with communities looking at urban forestry questions and in urban forestry plans and planning for community trees. I also work with a lot of woodlot owners so I work in the traditional forestry realm as well.
Nate Bernitz 2:09
Greg, is there anything unique about being a forester in Rockingham County?
Greg Jordan 2:14
Yeah, in some ways, being a forester; I think it's the same wherever you go. You know, trees growing in the forest are similar throughout the state, but Rockingham County... What's really cool about Rockingham County, it's sort of the, it's the collision zone between southern trees, you know, trees that are sort of at the northern end of their range. So southern species like hickories, and, spicebush, and other shrubs. And then we're at the southern range of sort of the Northern boreal species. So it's this collision of tree species. So it's a really diverse forest. And of course, the people are unique too, because Rockingham County is one of the more developed counties in New Hampshire. So we have this really cool species mix, but we do have a lot of people. We have a lot of smaller wood lots and we have more urban areas in a lot of parts of the state. So it's really is an interesting place to be a forester and an arborist. You know, you see all kinds of different trees, that foresters in the other part of the state, they just don't see the same thing that we do.
Nate Bernitz 3:19
Okay, so as we get into this conversation, I thought I'd start with a question for our resident horticulturist. So Emma, we're talking about trees today. Is there actually any meaningful distinction between a tree and a shrub?
Emma Erler 3:32
That's, a good question, Nate, and I think there's always some debate over whether something's considered a tree or whether it's considered a shrub. I've certainly read different definitions. I think the one I usually go with when people ask me this question is that a tree is a woody plant. So a plant that's perennial that lives for many years and actually has a bark and a rigid stem that exceeds 12 to 15 feet in height. And a shrub would be anything shorter than that. I also tend to think of trees as being woody plants that have just one or maybe two or three main stems, but primarily just one main stem or trunk, whereas shrubs tend to have multiple trunks that are coming up from the base or multiple stems,
Nate Bernitz 4:24
I thought we'd do sort of a cradle to grave talk on trees, it's that logical progression. So that means starting with selecting trees and planting trees and kind of ending our conversation on the end of trees' life when you when you have to do the work or hire and the big guns to come do it for you. But in terms of tree selection, there are some different considerations right? So one when you're buying trees is are you buying it bare root? Are you buying it sort of in that ball or burlap, are you buying it in a container? And then where are you buying it? So, Greg, what are your considerations as far as that first one? On what form you're buying your trees in? I know that at scale, right, if you're buying a lot of trees that might influence where you go just in terms of cost, but how do you think about that?
Greg Jordan 5:22
Yeah, it's a matter of practicality, I think, Nate. So you can buy, you know, bareroot seedlings, containerized seedlings or trees, and then of course, balled and burlapped trees. So the bareroot seedlings are one that that foresters work with quite a bit and conservationists work with quite a bit. You know, they're grown in nursery beds for several years. Then they get lifted and packaged for shipment without any soil attached to the roots. So that means they really have to be, not really have to, they have to be shipped during the dormant season. Right? And you can learn a lot about those, trees that are standard codes that come with bare root seedlings. So you might have something like a 3-0, that means it was grown for three years in a nursery bed. Or you might get something like a 3-2, and that's grown three years in a nursery bed and then two years in a transplant bed. So in New Hampshire, we're pretty limited when you get bareroot seedlings. It's really April and maybe the beginning of May because they have to be dormant. And when you get them, you really have to hurry to get them planted pretty quickly. There are ways to sort of heel them in, keep them for a bit before you can plant them. But you don't have a lot of time to spare. The containerized seedlings too, foresters sometimes work with those, we call those tublings. Right, those are grown in, in nurseries, or greenhouses. They come in specialized containers. They have a tiny little root system, but they're easy to plant because we use a little tool called a dibble that makes a little hole in the soil. And you just kind of pop those tublings into the into little hole. And so you have a little more flexibility on when you can get those tublings, and of course, other containerized seedlings or trees that we think of as potted trees. And those are pretty universally and easily accessible at, you know, nurseries and garden centers. That's really a great thing for a homeowner, I think. You know the only drawback with potted trees is that they can occasionally get pot bound. So you have to be a little bit careful about your selection of those trees. And of course then there is the bald and the burlap trees or the BNB trees. And those are fields grown. They're dug and transplanted into wire baskets that are lined with burlap. It's a really great way to get larger trees or those instant impact trees in the landscape. I recently planted a few at a school and we planted a giant three inch caliper tulip tree. Right, it had a giant ball we estimated it weighed, probably, 600 pounds. So it wasn't very easy for us to move around. So that's more of a landscaping or, you know, professional sort of tree to get. So that downside is that they're very, they're very heavy. So it's sort of an issue of practicality. Bareroot: easy to plant many, they're light, that's great. Potted: are sort of easy to move around for homeowners. The ball and burlap: that instant impact, but very tough to handle for for most people.
Nate Bernitz 8:16
And just backtracking for a second, would you define the term caliper?
Greg Jordan 8:21
So with bigger trees foresters and arborists are often interested in the diameter at breast height, that's four and a half feet above the ground. And that's where we take our standard measurements. But for nursery grown trees, those smaller trees, some of them might not even be four and a half feet tall. Or if they are, they're very small. So it's more of a practical way to measure the stem or size of the tree. And that's usually done at ground level or maybe six inches above ground level. So it's sort of a nursery term as opposed to more of a forestry term that we use in the woods.
Nate Bernitz 8:52
Gotcha. Emma, there's kind of an old adage that you should buy the biggest or oldest tree that you can. Do you agree with that adage? Or do you think that there are some reasons why you might not necessarily prioritize the age and size of a tree?
Emma Erler 9:12
Well, I think it depends a little bit on what your objectives are for that plant. In a landscape scenario, if you're looking for something that's going to have an immediate impact on the site, you know, visually or functionally, a lot of times you would probably go with the largest tree that you could get on the site that you could afford, because large trees are going to be quite expensive, these very big balled and burlap plants that that Greg mentioned. So in some cases, in landscapes, these large trees are probably the best bet. The only downside, and Greg kind of touched on this, is that when these field-grown trees are dug up, they often lose a lot of their root system. It's just inevitable with the machine that comes in to harvest them that you lose a good portion of that plant's roots. And it's not enough that the tree's really going to be harmed, but it is going to set it back quite a bit. So you may not see very much growth on that tree for some years. You know, you'll put it in, and you'll just kind of have the status quo for quite a while until that tree recovers from that stressful ordeal. However, if you go with a smaller tree, say this is something that's bare root, or a very small containerized plant that hasn't been in its container too long, and you put that plant into the landscape, it has most of its root system intact. It's not nearly as stressful to move a very small plant, as it is to move a very large plant, from the plant's perspective. So you tend to see growth that occurs a lot faster. So you know, some, in some cases, you know, you might, you know, break even, essentially, whether you started with the very small plant or the very large one, You just have to be more patient, right. So if you are hoping to have a nice looking shade tree on a site right away and not wait, you know, three, four, five or more years to have something that looks decent, then balled and burlap, biggest tree possible is the way to go. But if you're willing to be patient, and you ultimately want to see some some faster growth and potentially a healthier root system of that plant, then I would go with maybe that bare root plant instead.
Nate Bernitz 11:32
Okay, well, that could potentially be a money saver for people if they know that they can buy in that less expensive form and it's going to kind of explode with growth when you get it in the ground. That might make a lot of sense if you can be a little bit patient.
Emma Erler 11:47
Well and that growth won't be immediate, either. So it'll still be that first season where not a whole lot happens. But if you're if you're keeping up with your watering and fertilizing, in the years down the line, that plant should do pretty well, going forward. So yeah, I'd say a big part of it comes to price, how much money you have to spend, and then just what your expectations are for the landscape. If you don't want to wait decades to have a tree that is putting some shade on your property, then you probably spend the money to get something big.
Nate Bernitz 12:21
Right, and when you are going to actually purchase a tree, let's say that you are purchasing something containerized, do you have a preference, kind of in terms of selecting your vendor in terms of buying online or in person? Is it more that if you're buying in person, you're buying something containerized if you're buying something online, you're getting something bare root and then ball and burlap is something more that you have to preorder, I guess?
Emma E 12:52
Well, if you're getting bare root plants, you probably are going to have to order those in advance either from a catalog or online. Once a bare root plant's dug up out of the nursery or field situation, it can't be out of the ground all that long. So they're really not practical for most nurseries to have on hand, just waiting for a customer to come in. But if you're looking for a larger plant, something that's in a container, or balled and burlapped, I would recommend going in person to check out, you know, what your local nursery has in stock. You'll likely find some of both. Most nurseries are going to have mainly containerized plants. And that's just because they're easier to handle for most homeowners. They're not as heavy because they're not planted in heavy soil. They're in a soilless, you know, light peat-based mix, typically. And they're just smaller plants, something that somebody could put in the back of their pickup truck or their van or car pretty easily. But you can often still find balled and burlapped plants at the local nursery, there just won't be quite as many of them. And then of course, if you're looking for something that's very large, then you'll probably be working with a landscaper and they will source that plant for you from a wholesale nursery and get it into your landscape.
Nate Bernitz 14:18
And Greg one option, at least for property owners here in New Hampshire, is ordering through the state. They have a state forest nursery that's operated here. Can you talk a little bit about that and whether folks in other states might have access to a similar resource?
Greg Jordan 14:37
Yeah, the New Hampshire State Forest Nursery is really a pretty unique place. Over the years, you know, it used to be that most states had their own forest nurseries, and, that is probably because of budget cuts, that sort of has gone away for many states. But New Hampshire has maintained that nursery and they have quite a wide selection of plants that are used by Christmas tree growers, in conservation plantings, and also in landscaping. And like I said, they're bare root seedlings. So in New Hampshire, they can't be lifted until, you know, there's no frost left in the ground. So typically those come out in April, perhaps as late as early May. The state has a cold storage, so when they lift or take those seedlings out of the the nursery beds, they do go into cold storage. So they can be stored for a few weeks in the cold storage. And then, you know, shipped and quickly planted or heeled in by the homeowners or the purchasers. Folks, from other states can order from the New Hampshire State Nursery. But it really is a unique kind of New Hampshire thing that we still have our own state forest nursery. The time to think about that is to think ahead. Like Emma said, you do have to order these ahead of time. So you really need to be ordering, probably in December to get plants in April or May. And you have to think quickly or act quickly. They're very popular with Christmas, our state's Christmas tree growers. And so those, you know, Balsams and Frazier's and Canaan's all the furs, they will sell out very quickly. So it's really a highly respected and a place that produces really high quality bareroot seedlings,
Nate Bernitz 16:18
Something that I'll plug, and of course, we will put the link to find out more about the New Hampshire State Forest Nursery in the show notes here. But something I like to plug is that Extension volunteers actually help out at the State Forest Nursery, both from I think two of our programs: the Master Gardener Program and the Natural Resources Stewards Program. So that's a really exciting way that Extension is able to work with the state to offer that program, I guess I didn't realize that it was so unique. So I'm really grateful to have that for us.
Greg Jordan 16:51
It is a really unique place. Extension foresters, we are very close partners with the New Hampshire Division of Forest and Lands. So occasionally we find ourselves there volunteering as well, whether it's Patrick packaging seedlings during the lifting season, or we were there, you know, collecting seeds. A couple years ago, I collected a pail full of Northern Bayberry seeds. So they really do have some unique native species that are not easy to get in other places. You know, northern Bayberry, ninebark, different fruiting and flowering shrubs. So if you're looking for local native conservation seedlings, it's really a unique establishment.
Nate Bernitz 17:31
So we're recording this in kind of the middle of November. This is a time of year when a lot of times local nurseries might actually start to put some trees and shrubs on discount that they might not have been able to sell earlier in the year. What's your take on whether to kind of pursue those discounts and purchase trees and shrubs this time of year? Do you think that you can have success getting those into the ground and having them survive and do pretty well for you? Or is that something to be a little bit wary of. What's your take on that, Emma?
Emma Erler 18:05
Well, my take is that you're pretty much always better off buying plants at the beginning of the season, whether they're in containers or whether they're balled and burlapped. One of I think the biggest reasons for that is that when you get those plants early on, you know that they've had the absolute best care possible coming in from the nursery. Sometimes when these plants sit on that sale yard for quite a long time, unless there's a drip irrigation system installed in that pot, it can be really hard for employees to keep those plants watered really well throughout the entire season. And even if they've been cared for perfectly, it's still a lot of time for that plant to be sitting in a very cramped little pot, or in that wire basket with burlap. So the plants tend to not be quite as healthy when you get to the end of season as they were early on. So that's that's one consideration. Another thing to think about too, is the type of plant that you're putting in and how well it does transplant later in the season. You can potentially plant, you know, evergreens and deciduous trees in the fall. But you do want to, you want to do it early enough that they're going to have a chance to get somewhat established before the ground freezes and we get into the winter months. If somebody was trying to do that right now, and I think a lot of nurseries and garden centers may have already shut down for the season at this point. But ones that are that are still open and are still selling perennials or trees and shrubs, it might be just a little bit riskier from the buyer's perspective. Transplanting is inherently a stressful process, or a stressful event for a plant. And when you do it this late in the season, there's a good chance that plant's gonna have some winter injury. So that's something I keep in mind. I definitely don't transplant; I don't recommend transplanting any evergreens this time of year, whether it be broadleaf or needled evergreens. Maybe you might be able to get away with doing some deciduous trees, so trees that lose their leaves, let's say, a maple or an oak, but just know that there's a much higher likelihood that that plant is not going to survive. So I would, my baseline would be to the plant before the end of October, if you're going to do it in the fall. Otherwise, do it in the spring. And as long as you water throughout that whole first growing season, your plant should be in really good shape to make it through the winter.
Nate Bernitz 20:47
So Greg, in kind of a suburban setting, right, where people have these small- to medium-sized yards, where there are some varying site conditions potentially in different parts of the yard, you've you've got your: along the driveway, and along your your pathways settings, you've got, you know, out on the periphery of the property, the foundation of your house areas that you might want to be screening from, you know, for privacy from the neighbors, places like that. How do you talk to homeowners about how they can select the right plant for the right place, and really assess their site conditions and match trees to those conditions?
Greg Jordan 21:28
That's a mantra that arborists live by all the time, you know, right tree, right place or right tree, right site. So if you're a homeowner, you know, and you go and purchase these trees at a nursery, they're really quite small, but you have to think towards the future. And you have to think about what's the mature height? What's the mature canopy spread of the tree? What's the form or the tree? Is it columnar? Is it base-like? Has it got a broad spreading, you know, roundish crown? Is it an evergreen or deciduous tree? I mean, if it's a shade tree, and you're planting on the south side of your home, I mean, you want to be careful with planting evergreen trees. If you're looking for winter sun to warm your house, you got to think about its growth rate, the site requirements. One thing that a lot people sometimes don't think about, but sometimes they think about quite a bit is the fruits that the tree produces. I'll often be recommending, for instance, oak trees to people, but then they'll say, "I do not want to be raking up acorns off my lawn, it's a big hassle for me". Or they can be trees that produce fruit, like I like black gum, but it's a very attractive, produces a very attractive fruit that birds like and then birds end up you know, sitting over the driveway, and they have to go to bathroom and then the the seeds rain down on the car. And then you have to think about the hardiness zone. And so you really have to think about that final mature tree and what is its size? What is its requirements? What is its space requirements? And so you have to think really long-term. That's one thing that arborists and foresters are really good at is just thinking about the really long-term for a plant and where it's going to live.
Nate Bernitz 23:11
Emma, what can you add to that as far as maybe assessing and matching to some really specific site conditions that you might find in that suburban setting, like compaction, salt, other factors and maybe give some examples, if you can, of some trees that you might consider for some of these contexts?
Emma Erler 23:30
Well, you already listed two important ones, Nate! Compaction can be big if it's a plant that's going to be going in near a walkway, or a well-traveled piece of lawn or even, you know, right next to a street or driveway. That can be a tough growing location for a lot of plants. Salt, too is a concern. So if this is an area where there's going to be a lot of rock salt, whether again, it's right next to a road that gets salted, or a pathway or driveway, that's something to look at, too. In New Hampshire, it's not so much of an issue in any of our cities. But in some locations, you might also be thinking about air pollution, which can be an issue for a number of tree species. They really don't tolerate that. In terms of, you know, selecting which species you're going to put in these locations, it's a little tough, because you have to, you have to keep a bunch of things in mind, right? So you have maybe these limiting, tough factors like I just mentioned, like that salt or that compaction. It's also going to be important to pay attention to sun exposure. So if you have a site that's already partially shaded, some plants are going to do really well in that spot. Some are not. A lot of times, evergreens get really stretched out when you put them in the shade. They just don't tolerate that that well. And then absolutely, you're paying attention to the mature size you want that plant to be, right? So if you have a spot with powerlines overhead, you maybe can't have a tree that's any taller than 20 feet tall. And that's going to be important to research before you go out and purchase or plant that tree so that you are not constantly fighting that tree's natural growth habit as it matures. Meaning bringing in an arborist to do a bunch of pruning or, you know, trying to do some of that yourself. So when you have all these things figured out, you know, like what the what the soil is like the sun exposures, like what size that plant can be, and then you've considered some of those other factors that Greg mentioned, like seeds or fruits or you know, any of the other maintenance considerations, then you can start to try to narrow it down. Which, there are lots of great planting lists out there for different scenarios. For me, if we have a spot where I'm not concerned about height, let's say, but I need a tree that's going to be tolerant of compaction, I would probably be thinking of something like a honeylocust, a thornless honeylocust, which is a super tough tree. They're often planted along streets. And they have very fine foliage, which tends not to kill lawns, and you don't have to do much maintenance on. And a tree that Greg already mentioned, actually, is another one of my favorites. It's good for urban conditions, and that's the black gum. Really lovely fall foliage, it is a species that would live in wetlands typically. So that kind of lends itself to being okay in a bit more compacted soil. So that's another nice one to consider. And, gosh, there's there's plenty to talk about. One tree I would warn against, if it's going to be a real tough planting location, though, is sugar maple. Sugar maples are gorgeous trees. But they don't love salt. They really don't love compaction, they don't love heat. So if you have a really nice, healthy, moist, well drained soil, sugar maple could be an awesome choice, but it's probably not going to be real good for that droughty spot with poor soil right next to the road, or right next to the house.
Nate Bernitz 27:16
Greg, one situation that folks sometimes have who maybe live on a larger property. So we're going New Hampshire, northern New England, a lot of people are going to live on, you know, maybe a few acres, and sometimes people will look to clear some lands and start over or imprint their vision of what that space is going to be. What suggestions do you have as far as species selection and kind of general strategy for people that are on still small acreage, two, three acres, which is a pretty common lot size in a lot of the state and thinking about, you know, small-scale clearing and you know, establishment in those areas?
Greg Jordan 28:00
First of all, with people with two to three acres of natural forest, I tend to try to get to the think about maintaining that natural forest as opposed to clearing it. You know, those trees that are growing there have already demonstrated that they can grow on that site, typically very well. But sometimes it's not the species mix, or it's not the aesthetic that homeowners are looking for, you know, to cut down a lot of trees and then to convert to a plantable site is not cheap, it requires a lot of excavation. And so that's a really tough question to answer. And I typically advise against that strategy. You know, I often see this too, and around new housing developments where, you know, people who maybe not might not be tree people are clearing lots and then leaving certain species and during the construction there is compaction. And a lot of these trees like red maple, which they try to leave as shade trees, they really suffer when you alter that environment significantly. And so to leave as much natural forest undisturbed, that doesn't mean you can't go in and thin and maintain and favor certain trees, but to leave that native forest intact is really the best choice I think that homeowners can make. But if you do have a big site that is cleared, and then there's no stumps, there's so many species selections that you could make. Oaks and maples are very well suited to those sites where they can grow big. But generally I like to see native forest stay as native forest.
Nate Bernitz 29:32
And kind of building on that, I appreciate that, that word of caution. There are trees that tend to live under other trees: understory trees. What do you recommend for homeowners who might have, like you said, really established trees that are doing very well. You don't want to disturb those necessarily, but maybe you want to build more of a diversity in the understory. How might you approach that topic?
Greg Jordan 29:57
Sure, well, you can you know, underplanting is an option. And there are certainly species that we have native and they're also non-native species that are capable of growing in an understory of a forest. Typically, you know, if you introduce sunlight into a forest, you are going to have trees that come into the understory, whether they're your desired species or not. So far, as there's an arborist, we spend a lot of time actually managing sunlight. That's really what we do. And so if you want to introduce species into your forest, you may think, be thinking about thinning trees to increase sunlight on the ground, and then you're going to have native regrowth. Or if that's not the species that you want, you can certainly underplant, whether it's filtered light, and there's a lot of great species that we have that are that are suited to the growing in the understory of forests.
Nate Bernitz 30:52
Maybe you can give some recommendations, I think one situation a lot of people have is they're clearing out invasive species, and those and that clearing of invasives whether it's buckthorn or bittersweet, or, you know, whatever people are dealing with, it leaves gaps. And maybe to prevent those invasives from continuing to come back, people might be inclined to want to replace them.
Greg Jordan 31:16
Yeah, absolutely. That's a critical step of invasive species management. Typically, if we're doing mechanical invasive species control and your uprooting plants, as opposed to using herbicides, you end up with a lot of soil disturbance. And there's quite a seed bank. All those invasive plants, they produce a lot of seeds, and many stay viable in the soil for many years. And so as you do remove those from the forest, have a seed bank, you're going to have to continue to control those species, but you are going to want to capture that site. You know, fill it with some other plant material that's going to capture that growing space. If it's really sunny, I would typically recommend, you know, some sort of grasses or ground cover some sort of conservation seed mix. You know, if you're looking for woody plants, and maybe shrubs, it really comes down to the right tree or the right shrub on the right site. And so it's very site specific, but often, nature is going to dictate what will grow well there. If it's a, say a drier site, you may find that hazelnut does very well, on those drier sites. If it's very moist, and high nutrients, I tend to look at plants like spicebush, which I think is a really attractive plant and has nice flowers as a potential. If there's maybe a little more sunlight, maybe sassafrass as a small tree. So it really boils down to your preference and also what the site is going to dictate that can grow there successfully.
Nate Bernitz 32:42
Nice. I want to spend some time on actual planting and sort of other tree care, but Emma maybe before we do that, just while we're still on kind of species selection, could you touch on cultivars a little bit? A lot of times when we're shopping for trees, it you know, you might see that something is X or Y or Z, but a lot of times they're also going to have that cultivar name associated with it. How should that influence your thinking as a consumer, on whether to go with one thing or another?
Emma E 33:12
So a cultivar is, it's kind of a fancy word for cultivated variety. And these are plants that somebody either bred so that it developed certain characteristics - that could be a plant that grows smaller than the straight species would or has a slightly different color or shape leaf, maybe the fruit is a little bit different, more flowers, different bark, you name it, all sorts of options out there. And in the horticultural trade, by and large, what you're going to be able to find readily are cultivated varieties of plants. So if you're going out to buy, I don't know, let's say a red maple and you go to your local garden center, you're probably going to have a choice of, I don't know, half a dozen or so cultivated varieties that have a specific name added to them. I can't think of a single one right now to use as an example. But none of these are going to exactly resemble let's say the the straight, you know, wild species. They're probably going to have something about them that's exceptional in some way. Another thing that is often going for cultivars is that they tend to grow a little bit better in nursery pots too. So they might be a little bit easier for propagators to actually cultivate and grow seal CDs for that reason, or they might just perform a little bit better in landscape settings, then their, you know, just straight species native relative wood. All that said, if you were buying a plant for your landscape setting, a lot of times these cultivated varieties might be more appropriate for your site just because they are going to be smaller or they are going to be a little bit more ornamental. The thing to know about these though, is that for the most part, they are propagated asexually or clonally, meaning that cuttings are taken from a plant and rooted so they're not grown from seeds. They're all genetically identical. So if you were to buy one specific, let's say a Sun King Maple, every single Sun King Maple is going to have the exact same genetics, which for some people is important, or a big deal, as we lose native plant diversity. Having identical plants in the landscape might be important. If for some reason that plant is more susceptible to disease, let's say, if we have all identical individuals they're all going to be equally susceptible. So not something that I'm overly concerned about for the landscape. But if for some reason you were planting a larger woodland area, you probably wouldn't want all identical individuals in that setting. So then you would want seed grown plants. And if you are buying, typically if you're going to be buying seedling plants, or I should say bare root plants or trees anyways, usually these are seed-grown, you're more likely to run into plants that are cultivars if you're buying something that's in a container, or balled and burlapped. And I said cuttings before, the other way that trees are often propagated too is by grafting.
Nate Bernitz 36:42
So let's fast forward here to next May, May 2022, we're ready to plant some of the trees that we've maybe ordered over the winter, and have recently picked up in whatever form you're doing that in. Greg, can you share maybe some basic tips for planting trees and warn against any common mistakes that you see,
Greg Jordan 37:07
Planting a tree really isn't that hard if you understand the basics of trees. So again, you gotta have the right tree on the right side or the right tree in the right place, you want to think ahead on that regard. I see some common mistakes that that all kinds of people from professional to homeowners make when they plant trees. I have a saying that I sometimes use: that trees aren't tomatoes. And for gardeners, you know, I could be mistaken, but when I plant my tomatoes, I'll sometimes bury the stem because I feel like there'll be roots that come out of the stem. But with with trees you really can't plant them too deeply. Nor can you plant them too shallow, right? So we say plant it high, it won't die, plant it low, it won't grow. So when trees come out of a nursery, they have a root collar. There's a spot on the ground or - and you can see it on the stem. It's a color change or a swelling, and that's where that stem was located when it was in the nursery. If you bury that too deeply, you end up burying the stem and that the upper part of the stem, the bark is different than the bark they would find on the roots. It's not meant to be saturated constantly. So you end up with, you can have rot issues, insect issues, because it's constantly moist. And you also end up burying the roots too deeply and the roots need oxygen and so the tree will suffer in that regard. So you really need to be careful with the the height at which you plant your trees. And that's probably the most common mistake I see that that folks make when they plant trees. In other cases, a lot of folks will when they plant trees, they'll want to replace the native soil with an approved garden soil or loam. And when I plant trees, I will add a little bit of loam or compost to the planting hole and I'll mix it in, but it's not a straight, I don't do a straight improve soil. I want to use that native soil because the tree is gonna have to live where you plant it. And you want it to be able to survive and thrive in that native soil. And so what happens if you just fill up the planting hole with with an improved soil or loam, the roots will often get to the edge of that improved soil and then the trees are smart to say well the soil that's outside of here is not so great. And so rather than growing out, they can even start to grow back in towards the stem. And you'll end up with things like girdling roots where roots will encircle the stem and you can actually lead to killing your tree over time. And so those are two little tips that I think about when I'm planting trees. Those are great.
Emma Erler 39:52
I'm sure some of our listeners have been wondering how to transplant trees that are already established in the landscape, because that's a question we get all the time at UNH Extension. It's not uncommon to realize that a tree or large shrub has been planted in the wrong spot in your landscape. Ideally, we would always do our homework before planting to make sure that a tree will fit in a certain spot at maturity. But of course, that doesn't always happen. Transplanting trees successfully can be really challenging, and it's often worth hiring a professional with the equipment and knowledge to do the job. It's a risky proposition, because you will damage many of the feeder roots during the transplanting process. Feeder roots are responsible for absorbing the majority of essential nutrients and water to minimize shock to the plant. Root pruning several months to a year in advance is recommended. Pruning roots will encourage the tree to produce a new flush of feeder roots. The goal is to allow the plant to develop new feeder roots within the zone of the future root ball that will be removed. The larger the tree, the larger the root ball will need to be, which equates to more weight. I only recommend transplanting very small trees on your own. A one-inch caliper tree, for example, would need to have a 16 to 18 inch diameter root ball that's 12 inches deep. With that you're looking at a root ball that weighs well over 100 pounds. And when it's time to transplant, you'll need to carefully dig the soil away from that root ball and wrap it tightly with burlap before you move it to a new location. All of these things can be tricky when you're working by yourself to move a decent sized tree. In the process, it's also going to be essential that you try to keep the root ball as intact as possible to avoid breaking the roots inside. Though very tricky. transplanting established trees is possible with some careful work. If you think you'd like to move a tree in the landscape, I suggest checking out the factsheet from Penn State Extension in the show notes.
Nate Bernitz 42:09
Emma, maybe you can address a couple questions that we get pretty frequently with planting trees. So one is whether to stake your trees at planting. And the second is should you fertilize? And should you add those amendments that Greg touched on or peat moss and the other things that people are interested in potentially.
Emma E 42:29
Staking can sometimes be helpful, particularly when you're putting in very large trees, balled and burlap trees in particular. When those trees first go into the ground, they're not going to have a whole lot of stability from the root system. That root ball itself is pretty darn heavy, like the tree that Greg planted recently that probably weighed 600 pounds. But if you have an unstable soil, let's say it's really loose, sandy, maybe it's saturated, even, if you're planting in a wetter location. Or if you have a really high wind site, it is possible for that tree to shift in its planting hole. And when that happens, and you might have put that tree in the ground perfectly straight, but then it starts to tip over. And it's really hard to get that plant back upright again, once that's happened. So you know, what you can do to prevent that is to properly stake it. And there are different ways of doing this. But what's really critical when you're staking is that you are using materials that aren't going to girdle the trunk of the plant. There are, there's a specific tie you can buy that's like a nylon material that you can specifically use for staking trees. There are other flexible materials that you can buy that will stretch around the trunk of the tree. One of the real old fashioned things that people used to do when they were staking trees is to use a piece of garden hose over a wire or rope or something. I don't recommend that just because that puts a lot of strain on the trunk of the tree, a lot of pressure on it. And that's really something you want to avoid, because you don't want to damage the vascular system of that plant. And you certainly don't want to girdle it in any way, meaning you know, cutting off the, cutting off the flow. So if you do need to stake in an area and often you do with a large tree, I would definitely encourage you to look up some proper techniques and make sure you have some materials on hand that are meant for staking trees. And then I would use that staking just as a temporary measure. Typically trees aren't going to need that for more than a year or so. If you leave those stakes on for too long, you are increasing the risk of girdling the trunk and you might actually be hurting the plant in the long run because trees do actually build strength by moving a little bit with the wind. So if you completely cut off all movement of that trunk, you're going to end up with a weaker stem, ultimately. So it's more of just a temporary thing. You might have those stakes on for the first growing season, and next year you take them off or take them away, and your plant should be fine on its own. And then if you're putting in smaller plants, let's say something that's bare root, or something smaller in a container, typically a stake isn't going to be necessary, because that plant isn't going to be top heavy enough to really tip over in that planting hole.
Nate Bernitz 45:37
There is a lot to take away in what you were just saying, but something I couldn't help but think about was a conversation I had with someone a few days ago who was nervous about the fact that their trees, their large trees, were swaying in the wind. And they thought that those trees might fall on their house because of the way they were swaying. So they actually had an arborist come and top all their trees to prevent them from swaying. And I think what you said is just really important that actually that natural, swaying in the wind is, is perfectly fine and natural, not something to be concerned about. Because I think we'll talk about that a bit later, but chopping those trees is probably gonna make them more hazardous than than they might have been before, ultimately.
Emma Erler 46:22
Well, and kind of building off of something Greg said before, too, if you have a tree in an area that was just recently cleared, so say you left just a couple of trees standing that were formerly in the forest, they probably aren't going to be quite as strong if you get a storm scenario, because they grew up with all that support of trees around them. So those plants, kind of similar to staking, I guess, could be more storm-prone. But if this is a plant that's been growing out in the open for its entire lifecycle, it's probably going to be just fine unless there's some other serious structural defect with its trunk or root system.
Nate Bernitz 47:02
Value of continuity. Greg, is there any reason when you're planting a tree that you might want to do anything to protect it from the elements or from wildlife?
Greg Jordan 47:13
Well, definitely from wildlife, Nate, depending on where you live and what the deer pressure is. Deer can be quite an issue as well as some small rodents that are, you know, chewing the bark in the winter, especially when there's a heavy snowfall. And so you can put in - there are different tree shelters and wire cages that you can use to protect a small tree from from browsing by deer. As far as from the elements, you know, I've never, I always figured that trees are tough, they can handle the elements on their own. Certainly, if you're planting maybe some soft woods and they're in a very wind-exposed situation, you might want to use, you know, some anti-desiccants maybe to keep them from drying out over the winter and prevent wood to burn. But generally, if you can keep deerfrom browsing your trees, trees are able to handle the natural environment pretty well as long as you're selecting the right tree for the right site.
Nate Bernitz 48:07
So what might that look like just using some sort of like hardware cloth enclosure?
Greg Jordan 48:12
Yep. And there also are tree shelters which, and again, these aren't used for large trees, these are more for bare root or potted trees that you can actually put over the tree stem. They're kind of opaque and even the foliage can go inside of that shelter. For many years it will protect it from browsing from deer and other herbivores.
Nate Bernitz 48:30
So Emma, one of your recurring favorite topics is mulching and I don't want to deny you the opportunity to talk about that. So what do you recommend for mulching? I guess I would just ask any right or wrong way to mulch, do you mulch from the time that you plant? Do you keep mulch on your trees all year?
Emma E 48:50
I would definitely recommend mulching at the time you plant, in a landscape setting anyways, if this is in your yard. My main argument for that is that, well, there's a few, right? So one, that mulch is going to protect the soil, so it's going to limit soil erosion. It's also going to improve the moisture-holding capacity of the soil itself. So if it rains, or if you put down any irrigation, that mulch is going to slow down evaporation. So that's helpful. Mulch, I think most importantly perhaps with trees in the landscape, is going to protect the trunk from lawn mowers. So if you put a nice mulch ring around that plant, nobody's going to be tempted to get that last little bit of grass by getting the mower up close to the string trimmer up close. And honestly, for young plants in the landscape. If a vole or a deer doesn't get them, so often it's the lawn mower that ends up taking them out or weakening them for the rest of their life. So having a mulching around the plant is important there too. I think where we start to run into issues with mulch is when we use too much of it. A lot of times what happens is that people put more mulch around their mulch circle on their tree every single year, that spring freshen-up, right? Because everybody likes the look of fresh mulch and the smell of fresh mulch. But if you're using a bark product or a shredded wood product, these materials don't break down very quickly, it's gonna take them a few years to fully decompose. So if you're putting more of that material on every single year, it can build up over time. And often, what happens is that you get this mulch layer that stacked up against the trunk of the tree. Just like Greg mentioned, planting a tree too deep, you can kind of do the same thing to it just by stacking too much mulch around the base. So you may have started out with a perfectly planted tree that's at the right level. But if you keep piling mulch around its base, particularly right up around its trunk, you can start to have issues with the decay, where there's too much moisture there for too long. So that's something to be avoided. And when you are mulching, what I would urge you to do if you're making a circle around a tree, is to put enough mulch down to make it out to the drip line of the tree. So that is essentially the furthest out branches from the trunk all the way around in a circle, where you would picture the, you know, water sheeting off that tree at its furthest most point. Because that's going to be where the majority of the trees roots are located within that circle. So if you can protect that soil with mulch, that's going to be the ideal.
Nate Bernitz 51:48
So does that mean that that mulching might potentially grow in diameter over time?
Emma Erler 51:54
It does mean that, yeah. If you, a lot of times if you go to an arboretum, so a place where maintaining tree collections is really the objective, you'll find very, very large mulch rings around the trees in the collection. This might not always be practical in a backyard situation. But in a lot of cases, I think it makes sense. Because as that tree gets bigger, it's going to be much harder to grow grass under that tree because there's going to be too much shade. So expanding that mulching makes sense. And if you're not looking to mulch, then putting a heavy shade-tolerant ground cover beneath the tree probably makes more sense than trying to have grass in that same location.
Greg Jordan 52:38
For younger trees, and when it comes to mulching, and then what Emma was describing as what I call volcano mulching, when you're piling it up and it looks like a cone of volcano around a tree. If you do a tree like that, you can certainly pull that mulch back away from that. What I typically recommend to homeowners for newer trees or younger trees is the rule of threes, which is a three-inch layer of mulch in a three-foot diameter circle around the tree, leaving a three-foot, sorry, three-inch gap between the stem and the mulch just to keep all the mulch off the stem.
Nate Bernitz 53:10
Something that's just as important as mulch, especially for young trees, is irrigation. I know that you both can talk from multiple levels here, but Emma certainly can talk in that fine gardening sense. You plant that that one tree, and you're going to give it lots of TLC, maybe Greg you can talk about, maybe you're planting quite a few trees at a slight, slightly larger scale. Irrigation might be a different animal in those two situations where you might be able to keep that one tree watered more easily than you could many trees. So what would you say is kind of the bare minimum as far as providing irrigation for newly planted trees and what strategies do you recommend at those two levels? You want to start Greg?
Greg Jordan 54:05
Sure, well, Nate, you know, in a forest or at a large scale, unfortunately for the trees, they're kind of on their own. Right? They're going to have to thrive with what water that nature provides them. It's not practical to irrigate large areas and water trees. When you plant in the spring, which is an ideal time to plant as Emma suggested, you're hoping for rain in those those situations, especially when you're planting the little bare root seedlings. And certainly sometimes with native regeneration, the forest is trying to get young trees to grow in the forest and when we have significant droughts like we did, we'll sometimes have years where we lose a lot of seedlings, that's just natural. I think it's tough to prescribe how much water a tree needs. It's very species-dependent and site-dependent. I typically fall back on an inch per week as ideal. And so for me, for instance of the trees that I recently planted, some larger balled and burlap trees, they weren't very close to irrigation, so I had to hoof buckets, I have five gallon pails, out to those trees. Twice a week I gave each tree two five-gallon pails worth of water. So for me, that was sufficient, I think, to get those trees a good start and I'm still continuing to water them once per week right now as we go into the dormant season. So five gallon pails work, you can use your garden hose and maybe figure out your flow rate, how much water to give a tree. Sometimes I'll use a trickle out, I'll drill a few small holes into the bottom of a five gallon pail so it slowly trickles out into the soil, so it doesn't all just run off if you splash that five gallons right onto the soil. So again, when you're in those bigger situations, you cross your fingers. Those little trees are kind of on their own unless you're willing to do the labor to hoof water out to them. But when you're a little closer to a water source, I think an inch per week, but that's just my my feeling.
Emma E 56:04
And I would actually agree, Greg. That one inch a week is what I fall back on as well for all trees and shrubs that are going into the landscape. You know, if you have a tree that's planted near, a hose someplace where you can get it water pretty consistently, it's fairly easy to do. In some cases, you might just leave a sprinkler setup in that area so that you can run that once or twice a week. Or you know, probably better yet, you might have some sort of drip tape or drip hose that you set up around underneath the tree. What I've seen work really nicely, at least for larger b&b trees that have gone in is actually wrapping a drip hose around that tree more or less than kind of a circular, too, in a circular effect, so that you're you're getting moisture down to that tree's entire root system, and you're not wasting any water with overhead watering. But lower tech options like the bucket you mentioned with the holes drilled in it work. They're also all sorts of other just, let's see, watering systems you can buy for new trees or different bags that either hug the root system of the plant or go around the trunk of the plant that you fill up with a hose and the water slowly percolates out from. I think those are probably best suited to maybe park situations where somebody doesn't have a whole lot of time to water that tree, but they can come by and fill up that bag with a hose and then walk away and do it again the next week. But if this is just a tree in your backyard, probably easy enough to do it just with those five gallon buckets with a sprinkler, maybe that drip hose and watering for throughout the whole season, whole first season anyways. is going to be critical. Getting new trees through their first winter is probably the the biggest challenge. Even with some of the native species, they can be very prone to injury from the winter conditions, whether it's freezing or thawing, whether it's southwest injury, from sun exposure on their southern side in the winter months, or just from cold. The more we can irrigate them appropriately throughout the growing season and through the fall, the more likely that plant is going to be to survive the winter.
Nate Bernitz 58:33
And going into year two, are you kind of off the hook at that point on irrigation? Or do you still need to do some maybe supplemental watering over the summer?
Emma E 58:41
I don't think you have to be quite as worried about it, but it's still going to be important to do some. If we get into a really severe drought, for example, giving that tree some water is going to be helpful, particularly if this is a balled and burlap plant or even a containerized plant that you spent a significant amount of money on.
Nate Bernitz 59:01
Right. So, Greg, I'm curious in kind of an urban forestry setting, do you view fertilizer as having any role? Or is that really not something that you're going to deal with a whole lot? What is that line between trees that really don't need fertilizer and trees that do or is fertilizer always kind of a bonus? Like how do you both think about that for trees?
Greg Jordan 59:27
I'm not someone that typically fertilizes trees. Certainly Christmas trees I have fertilized and you want that, you know nice lush green growth. In a typical, say suburban environment, I know we're talking urban as well here, I always feel that a mature tree can basically get all the nutrients that it needs. It has a pretty well established root system. Unless the site is really poor, the trees are really good and they learned to be thrifty, if they need to be, and live on less nutrients and even less water if it's needed. And so I'm not some that spends a lot of time fertilizing trees. If you're someone that maybe fertilizes your lawn, I think that's probably enough for most trees to get by on. Real urban trees, I think, that's a whole different animal and urban trees, I mean, it's really a harsh life for them. Urban trees might live a decade, if they're lucky. In a real urban area they're often planted in what we call tree pits, these tiny little bits of soil and the roots have very little place to go. In those cases, I think, perhaps fertilizing trees would make some sense. Again, I would want to pick a species that's really tolerant of some of the poor soil conditions. But if I had a tree in a tree pit, I would consider fertilizing that tree. I'd want to do a soil test first to see if what nutrients it actually really needs.
Nate Bernitz 1:00:54
What's your take on that Emma?
Emma Erler 1:00:56
I would say really the same that I really can't think of too many examples in my experience of trees that needed extra nutrients to be added. Not trees that were in the landscape. As long as there's some organic matter being broken down in the area, that that could even be lawn, whether it's just grass clippings that are breaking down or leaves that have been ground up by the lawn mower, there's going to be nutrients in the soil for the tree. But I would agree with Greg, if you have a scenario where that tree has a really limited root system for some reason. Like in those streetside, tree wells, or maybe even in, I don't know, a tight parking lot island or something, it could be helpful to give that plant a few more nutrients. One reason that you might not fertilize trees, because they're certainly, you might see a boost and growth from that. But it might be if you have a small area where this plant is going to fit, you might not want to be giving it a whole bunch of extra nutrients. Because you don't want it to be overly happy in that location and get too big for the spot where you've planted it.
Greg Jordan 1:02:16
If we're talking about sort of an integrated pest management approach, Nate, and we're talking about fertilizer, down on the seacoast we have quite an issue with the hemlock woolly adelgid, which is sort of a non native insect that feeds on on our Hemlock trees. And the trees are really suffering right now between the drought and several warm winters in that the Adelgid has done really well. And people often want to do something to help their trees. Watering would be helpful to those trees because those insects are taking some of the sap out. But then they tend to want to fertilize those trees as well. And what ends up happening as you fertilize those trees, you're actually feeding the insect. And so you want to think kind of holistically about your trees and fertilization as well. So sometimes it's better just to hold off and not feed the trees in that case.
Nate Bernitz 1:02:59
Gotcha. And we did an episode on fertilizer awhile back and we don't need to really go into that more deeply now, but I'd encourage people if you want more of a deep dive on fertilizing plants to check out that previous episode
Emma E 1:03:24
This episode's feature plant is tamarack (Larix laricina). Also known as American larch, tamarack is the only native conifer in New Hampshire that drops its needles in the fall and grows new ones in the spring. It is a tree of very cold climates, and it's most common in northern New Hampshire, growing in boggy soils and woodland areas. Tamarack can be considered a medium - to large-sized tree that typically grows 40 to 60 feet tall in a pyramidal shape with horizontal branches. Its needles grow and brush like clusters at the ends of short spur-like chutes long branches that are a little over an inch long (the needles, not the spurs). It also forms distinctive round cones that are about an inch in diameter. In the fall, tamarack needles turn from green to showy yellow before falling to the ground. It's a great choice of tree for areas with wet soils, such as the edges of ponds, or large rain gardens. Before we close this episode, I have one more tip I'd like to share. If you're planning to bring a new tree or shrub home from a garden center, make sure you know how to transport it properly. First, never pick up trees by their trunks, or drop them on the ground. Lifting a tree by the trunk can damage the bark and dropping a tree, whether it's in a pot or balled and burlap, can break the roots. Always lift trees by their pots or root balls. It's also important to protect trees from the wind on the drive home. Wind will strip water from the leaves and exacerbate stress at transplanting. Whenever possible, transport trees inside of a vehicle when leaving the nursery. If you're using a pickup truck, however, wrapping or covering the tree or shrub with a tarp will also do the trick. Trees are a big investment, so make sure you take good care of them from the very beginning.
Nate Bernitz 1:05:25
And that's your closing gardening tip. Before we go, I want to let you know about a great webinar we have coming up on garden and landscape design for winter interest and wildlife. Emma is one of the presenters and we'll share a variety of trees, shrubs, perennials and grasses that contribute interesting bark, flowers, berries and other features to your yard and garden over the winter with visuals. And our colleague Matt Tarr will share some of the small changes you can make in your yard and garden to welcome and support wildlife. This webinar is on Monday, December 6 at six o'clock. You do actually need to register for this webinar and you can find the link for that in the show notes. I also want to again plug our listener survey, which asks a few questions that will help us understand the impact of the podcast and to improve it to better meet your needs. As an incentive, because we'd like a lot of responses, we're doing a giveaway. One person who completes the survey will be randomly selected to receive a pair of Felco pruners. These are hand pruners from a reputable vendor and should last and perform for many seasons. Find the link to the survey in the show notes, and thank you for taking the time. Thanks for tuning in to this episode of Granite State Gardening. Plan to listen to part two of this episode and until next time, why don't you try and identify all the trees in your home landscape if you haven't already, and start thinking about whether you might want to make any additions in the spring. We'll do more on tree care and cover a wide variety of tree problems and solutions in part two, which we'll get into your podcast feeds soon.
Granite State gardening is a production of University of New Hampshire Cooperative Extension, an Equal Opportunity educator and employer. Views expressed on this podcast are not necessarily those of the University, its trustees, or its volunteers. Inclusion or exclusion of commercial products in this podcast does not imply endorsement. The University of New Hampshire, US Department of Agriculture and New Hampshire counties cooperate to provide extension programming in the Granite State. Learn more at extension.unh.edu.
Transcribed by https://otter.ai. Transcript edited by Rebecca Dube.