Blueberries are a very popular fruit in the United States because of their unique flavor, small edible seeds, and ease of preparation. Blueberries can be eaten fresh or used for jelly, jam, pies, pastries, or juice. Blueberry fruit is also low in calories and sodium, contains no cholesterol, and is a source of fiber. A major constituent of the fiber is pectin, known for its ability to lower blood cholesterol. Blueberries contain measurable quantities of ellagic acid, which has inhibiting effects on chemically induced cancer in laboratory studies. Blueberry juice also contains a compound that prevents bacteria from anchoring themselves to the bladder, thereby helping to prevent urinary tract infections.

Growing Blueberries in the Home Landscape:

Blueberries are a good fruit crop for home gardens because they require little space. Blueberry plants require highly acidic soil conditions for best results. Blueberry plants begin to produce fruit in the third season; however, they do not become fully productive for about six years. Once in production, it is necessary to protect the fruit from loss to birds. Climatic Requirements: Plants are generally not hardy when temperatures drop below -20 degrees F.

Site and Soil Requirements for Blueberry Production:

The highbush blueberry requires full sun for optimum yield and quality, and grows best where the soil is very acidic and well supplied with moisture. Soil pH should be between 4 and 4.5 and contain at least 4 to 7% organic matter.

With loam soils, it is suggested that plants be grown on raised beds, 4 feet wide and 9 inches high for better water drainage. Such beds are not needed for production on sandy soils.

Soil Preparation:

It is very important to test soil for pH, nutrient status and organic matter content before conducting soil preparation. See GreenShare Factsheet on soil testing for more information. Your soil should be tested twice; once before soil preparation and acidification, and once after sulfur and fertilizer have been added. Further adjustments may then be necessary. Increase soil organic matter by adding grass clippings, manure or leaves (not red maple or beech) according to soil test recommendations. Incorporate the materials into the top 4 to 6 inches at least one year before planting.

Suggestions for Soil Acidification:

If soil pH is above 4.5, apply granular sulfur to lower soil pH. The material should be well mixed throughout the top 4 inches of soil, three months before planting.

Planting:

At planting, dig a hole18 inches deep and 18 inches wide and mix 1 cubic foot of peat moss with top soil until the hole is filled 4 inches from the top. Set the plant and cover the roots with the remaining peat-soil mix. Set plants 5 feet apart with rows 10 feet apart. Apply 4 inches of sawdust or wood-chip mulch in a 2 feet wide band after planting, and maintain a 4 inch depth and 4 feet band over the life of the planting.

Fertilizers:

Fertilizers for blueberry production are best applied using soil test results as a guide. At planting, apply 1/2 to 2/3 pound of ammonium sulfate (or 10 to 16 ounces of 10-10-10) per 100 feet of row 4 weeks after planting. Keep fertilizer at least 6 inches away from plant.

In the second through twelfth years, apply 1 to 1.5 pounds of ammonium sulfate (2 to 3 pounds of 10-10-10) per 100 feet of row each year for fertility and acidity maintenance. Apply 0.5 pound of the ammonium sulfate at bloom, and the remaining 0.5 pound 4 to 6 weeks later. If plant leaves become chlorotic, apply 2 to 3 ounces of ferrous sulfate or iron chelate around the base of the plants each year.

Watering:

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. In dry seasons, supplemental watering is essential to obtain good yields of high quality products. Do not water after early September unless soil is very dry.

Pruning:

Blueberry plants normally do not need to be pruned for the first three years. Remove blossoms that appear in the year of planting and second year after planting to stimulate vigorous growth. It is important to know the anatomy of a blueberry bush before attempting to prune blueberries. During the fourth year, the dormant plants should be pruned in mid-March. At this time, remove dead and weak branches and thin, terminal wood with small buds. Prune interior crossing branches to admit light to the center of the plant.

In subsequent years, thin out older branches to force new growth. Tall-growing branches can be headed back and thin branches removed. Flower buds of blueberry bush are produced on tips and down the second year old shoots. Blueberry bushes tend to produce smaller berries when they are overloaded with fruits, making it important not to have too many flower buds.

Mulching:

Generous use of mulches such as sawdust or peat moss will help control weeds, conserve moisture and keep roots cool. Increased organic matter from decomposing mulch will help improve soil structure and nutrient uptake of blueberry bush. Replenish mulch as needed to keep the mulch depth at 2 to 4 inches.

Insects and Diseases:

Some potential insect problems in blueberries 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.

Adapted from Gary Gao, Ohio State University Extension, 2000