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. Once established, an annual application of an acid-producing fertilizer, such as ammonium sulfate, in early spring is sufficient for blueberries. Ammonium sulfate supplies nitrogen to the plants and also helps to maintain soil acidity. In Iowa, blueberries generally have few insect and disease problems.
Birds are the biggest threat to the crop.
If left unchecked, hungry birds may devour much of the crop. While scare devices may be helpful, netting is the most effective way to protect the crop. Netting should be placed over the plants when the fruit begin to turn color. Hang the netting over some type of support structure with the edges of the netting buried or anchored to the ground to prevent bird entry from below. Blueberries don't have to be relegated to the backyard garden.