The highbush blueberry is a deciduous shrub native to eastern North America, but it can be grown in many environments with proper care and maintenance. It is the most commonly grown commercial blueberry in the United States, and is also popular among gardeners for its high yield of fruit. However, the highbush blueberry plant requires a very particular growing environment and does not produce fruit for several years after planting.
Plant highbush blueberry in early spring in an area that receives full sunlight and has well-drained, slightly acidic soil rich in organic matter. Add a 2- to 3-inch layer of organic compost to the planting site and use a garden tiller to incorporate the mixture into the soil.
Dig a hole about 18 inches deep and combine approximately 1 cubic foot of peat moss with the removed soil. Cover the roots with the soil and peat mixture to about 4 inches from the soil line. Fill in the remainder of the hole with pure peat moss. Space plants 5 feet apart for the best results.
Apply a 4-inch layer of sawdust mulch around the base of highbush blueberry plants immediately after planting. Maintain the mulch year round by adding more as the layer decomposes, always keeping a depth of at least 4 inches. Make sure the soil is moist before adding the first layer of mulch.
Apply 2 oz. of a balanced fertilizer to the soil surrounding the highbush blueberry plant 3 to 4 weeks after planting. Spread the fertilizer in a circle around the plant, beginning at least 6 inches away from the base and ending 15 to 18 inches from the base. Apply the same amount of fertilizer the next year in spring. Add two additional ounces of fertilizer for each additional year of growth.
Water highbush blueberry plants immediately after planting and regularly during the spring and summer months. Soak the soil to a depth of 1 to 2 inches per week. Do not water after early September, unless the soil is extremely dry. Blueberries have shallow root systems and are sensitive to overwatering.
Remove flower clusters from 1- and 2-year-old highbush blueberry plants to encourage root development and discourage fruiting. Plants should not be allowed to fruit for the first 2 years after planting. Leave several small flower clusters on the plant in the third year to produce a small yield of fruit. Allow the plant to fruit naturally in the fourth year.
Use pruning shears to remove dead or damaged branches from highbush blueberries while they are dormant in winter during the first 3 years of growth. Prune fully from the fourth year on by thinning branches to promote new growth and removing any canes that are more than 6 years old.
Harvest blueberries when ripe in early to late August. The fruit should be picked about 1 to 3 days after they turn blue. Make sure there is no hint of red color visible on the berries before harvesting.