Should I use landscape fabric to keep weeds out of my perennial garden?
For those who dread weeding, landscape fabric covered by a few inches of mulch may seem like the perfect solution for shrub and perennial beds. The idea behind using landscape fabric is that it will permanently eliminate the need to weed the garden by forming a barrier that blocks weed seeds from germinating, while still being porous enough to allow water to reach the roots of shrubs and perennials. If that sounds too good to be true, that’s probably because it is. Although landscape fabric initially does a wonderful job of suppressing weeds, as time goes on, it can become a maintenance nightmare.
Any mulch or soil on top of the landscape fabric can support weed growth, a problem that is especially difficult to handle when weeds take root through it. This is particularly problematic with perennial weeds. Once their root systems have penetrated the landscape fabric, they can be almost impossible to pull out. The best option at that point is to remove the landscape fabric entirely, which is no small task. In this process you may end up damaging the root systems of your landscape plants too, as tree, shrub, and perennial roots may also grow through the landscape fabric.
Even if weeds are not an issue, landscape fabric seems to invariably become exposed. Once it is above the surface, it is nearly impossible to effectively tack down again. It will generally remain an eyesore until it is removed.
In addition to making weed control difficult, landscape fabric can also prevent water from getting to plant roots. Over time, small particles of soil or mulch can fill in the small pore spaces in the landscape fabric, reducing the amount of water that reaches the soil beneath. Due in part to this reason, plants mulched with landscape fabric are often not as healthy or vigorous.
In almost all scenarios, the best way to suppress weeds in a perennial garden or shrub border is with an organic mulch. Shredded wood mulch is great at controlling weeds, is very attractive, breaks down gradually, and may only need to be replaced every other growing season. Shredded leaves and pine needles are also excellent mulching materials that many thrifty gardeners will already have on hand. As long as the garden has been thoroughly weeded before mulching, and the mulch is applied at an appropriate depth, you can expect to avoid too much weeding.
Do you love learning about stuff like this?
Got questions? The Ask UNH Extension Infoline offers practical help finding answers for your home, yard, and garden questions. Call toll free at 1-877-398-4769, Monday to Friday, 9 a.m. to 2 p.m., or e-mail us at firstname.lastname@example.org.