Fresh blueberries are one of summer's best tasting treats. They are excellent in pies, muffins, and pancakes. Blueberries are also a great topping for breakfast cereals. Blueberries can be successfully grown in Iowa. However, they do have special growing requirements.
The blueberry is a member of the Heath or Ericaceae Family. Blueberry plants require a sunny location and well-drained soils high in organic matter. Avoid wet, poorly drained soils. Blueberries are susceptible to root rots in poorly drained soils. Gardeners with poorly drained soils can improve drainage by incorporating organic matter and planting in raised mounds or beds. Soil pH is also extremely important. Blueberries require an acid soil of pH 4.0 to 5.5. Since the pH of most Iowa soils is above this range, the soil pH must be lowered to successfully grow blueberries. Gardeners can lower their soil pH by adding Canadian sphagnum peat to the soil. When planting blueberries, backfill with a mixture of 1/2 (moist) peat and 1/2 soil.
Two types of blueberries (highbush and half-high blueberries) can be grown in Iowa. Highbush blueberries are hardy in central and southern Iowa. Plants develop into 6 to 8 foot shrubs. Suggested varieties for Iowa include 'Blueray', 'Patriot', 'Elliott', 'Coville', and 'Collins'.
Half-high blueberries possess greater cold hardiness and are the best choice for gardeners in northern Iowa. Plants are relatively small (varieties commonly grow only 1 to 2 feet tall) and produce small to medium size berries. Suggested varieties are 'Northblue' and 'Northsky'.
Spring is the best time to plant blueberries. The roots of dormant, bare-root plants should be soaked in water for about an hour before planting. Dig a hole approximately 18 to 24 inches deep and 2 feet wide. Set the plant at the same depth it grew in the nursery. Then backfill with a 50:50 mixture of soil and moist peat. After planting, prune back the plant by 1/2 by removing the small side branches and by heading back the main branches. Also, thoroughly water each blueberry plant. Highbush blueberries should be spaced 4 to 6 feet apart. A 3 to 4 foot spacing is adequate for the smaller half-high blueberries. Plant 2 or 3 blueberry varieties to insure adequate pollination and fruit set. Blueberries have a shallow, fibrous root system. Plants quickly become stressed during hot, dry weather. To help retain moisture and control weeds, apply 3 to 5 inches of mulch around blueberry plants. Sawdust, wood chips, pine needles, and shredded leaves are excellent mulching materials. During dry weather, water plants weekly. Blueberry plants should not be allowed to bear fruit the first 2 years after planting. Any blossoms which form should be removed. Removal of the flowers will maximize vegetative growth and increase yields in later years. Blueberry plants should come into full production by the fifth or sixth year. Gardeners can expect to harvest 5 to 10 pounds of fruit per plant from mature highbush blueberries. Half-high blueberries generally produce 1 to 3 pounds per plant. Blueberries don't have to be relegated to the backyard garden. Blueberries are also attractive ornamental shrubs. Plants produce white to pink, urn-shaped flowers in the spring. They also produce excellent fall leaf color. The fall foliage consists of shades of yellow, orange, and red.
This article originally appeared in the March 22, 1996 issue, p. 35.