By Jeremy DeLisle, UNH Cooperative Extension Education Center Program Coordinator
Q: My kids love blueberries and I’d like to grow them at home. Could you offer some advice? – Sarah B, Tilton, NH
Blueberries are the easiest of the small fruits to grow. They are also one of the most healthful fruits, containing vitamins and minerals as well as anti-oxidants. In northern New England, blueberries begin to ripen in early to mid-July and reach their peak in early August. About five years after planting you can expect to harvest four to eight quarts of berries per mature bush.
Soil pH is critical for blueberries
Blueberries require an acid soil with a pH range of 4.5 to 5.0. Have your soil tested to determine the pH level. If the pH level is too high, apply fine ground sulfur or aluminum sulfate to bring it down. A site with full sun all day will give the best results.
Minimize moisture stress and weed competition
Plan to plant healthy 2- or 3-year-old plants in early spring. Dig a hole that is at least twice as large as the blueberry plant root system. Set the plant slightly deeper in the hole than it was set in the nursery, backfill with good topsoil and water thoroughly.
Blueberry bushes have a shallow root system and require mulch, both for conserving soil moisture and minimizing competition from weeds. Use a 3- to 4-inch layer of sawdust, bark, pine needles or leaves, or a combination of these.
Do not mound mulch around the base of your plants. This is known as a mulch volcano, which creates a great habitat for voles, which love blueberry bark. Instead, spread mulch evenly over the planting area.
Plan to supply sufficient water
Watering regularly, especially during the establishment year, is critical. Plan to water twice a week during dry periods, thoroughly wetting the area around the root zone to a depth of several inches. Drip irrigation can be a great choice for blueberries and other small fruits. Soaker hoses, drip tape or plastic irrigation pipe with drip emitters ensures your plants get plenty of water, while leaving most weeds high and dry. Lines can be placed in the planting bed so that roots can easily access water. Some lines are designed to be covered with soil or mulch, while others can be left above ground for easy access.
Choose suitable varieties
For southern New Hampshire, Patriot, Blueray, Bluecrop (avoid wet sites with this one) and Jersey highbush blueberry cultivars are recommended. For northern areas, Northland, North Country, Northblue, St. Cloud and Friendship highbush/lowbush cultivars perform best.
First year care
Remove blossoms the first year to encourage plant growth. Do not fertilize at planting time. Instead, wait two to three weeks for the plants to get started, then apply no more than 1.5 ounces of 10-10-10 fertilizer, or up to 3 ounces of an organic fertilizer blend such as 4-6-4. Fertility requirements will increase annually until the plants reach 6 years of age. The publication Growing Highbush Blueberries provides a simple chart with fertility recommendations, as well as additional details about how to raise a great crop of blueberries.
Blueberry bushes can live for many years. It is not uncommon to find plantings 30 years old or more. With proper care, you will be harvesting delicious fruit for years to come.
Jeremy DeLisle is the program coordinator for the UNH Cooperative Extension Education Center. The center answers questions about gardening and more at firstname.lastname@example.org, or by calling (877) 398-4769 Monday through Friday, between 9 a.m. and 2 p.m.