Blueberries require a small space for growing but require highly acidic soil conditions for best results. Few backyard soils in Ohio are naturally acidic enough to grow good blueberries. Therefore, the gardener must amend the soil with organic matter and also must correct the pH and acidify the soil at least one year before planting. Soil pH should be in the range of 4 to 4.5 and have 4 percent to 7 percent organic matter or more. Blueberry plants don’t produce fruit until the third season and do not become fully productive for about six years.
There are three main types of blueberries: highbush, rabbiteye and southern highbush. Only highbush blueberry is recommended for Ohio. The other cultivars are best grown in the South. In general, the climate throughout Ohio is suitable for the production of blueberries. They are not hardy, however, in temperatures below -20 degrees F.
Blueberry bush requires full sun and must be well supplied with moisture. When planting, dig a hole 18 inches deep and 18 inches wide and mix 1 cubic foot of peat moss with topsoil until the hole is filled 4 inches from the top. Set the plant and cover the roots with the remaining peat-soil mix. In heavy soils, an equal amount of peat can be mixed with an equal amount of soil. Set plants 5 feet apart with rows 10 feet apart. Apply 4 inches of sawdust or wood-chip mulch in a 2-foot-wide band after planting, and maintain a 4-inch depth and 4-feet band over the life of the planting.
Do not indiscriminately apply fertilizer to blueberry bushes. Rather, fertilizers should be geared to soil test results. When fertilizing, keep it at least 6 inches away from the base of the plant. Blueberry bushes have very shallow root systems and are very sensitive to water fluctuations. They need at least 1 to 2 inches of water per week. Be sure to provide supplemental watering in dry seasons. Do not water after early September unless the soil is very dry.
Do not prune blueberry plants for the first three years. Remove all blossoms for the first two years after planting to stimulate vigorous growth. In the fourth year, prune dormant plants in mid-March. Remove dead and weak branches and thin wood with small buds. Prune out crossing branches on the inside of plant in order to admit more light. From the fifth year on, thin out older branches to force new growth. Top out tall-growing branches and continue to remove thin ones. Flower buds of blueberry bush are produced on tips and down the length of second-year-old shoots. Blueberry bushes tend to produce smaller berries when they are overloaded with fruits, so it is important not to have too many flower buds.
Apply mulches generously to help control weeds, conserve moisture and cool the roots. Decomposing mulch will increase the organic matter in the soil and nutrient uptake of blueberry bush. Maintain the mulch depth at 2 to 4 inches.
Potential insect problems include blueberry tip borer, plum curculio, cranberry fruit worm, and cherry fruit worm. Disease problems include mummy berry, powdery mildew, twig blights, botrytis blossom blight, leaf spots, and cane gall.
For more information, call the Ohio State University Summit County Extension and request Fact Sheet HYG-1422-98, “Growing Blueberries in the Home Garden.”
Source: Akron Ohio News, Dayle Davis