Growing Blueberries in Nebraska
Blueberries are a wonderful small fruit and a favorite of home gardeners in the eastern United States. Many people, both native Nebraskans and new residents from eastern climates, yearn to grow blueberries in Nebraska gardens. However, this is not an easy proposition throughout most of our state. To grow well, blueberries require porous, moist, sandy soils high in organic matter with a pH range of 4.0-5.5. Most native Nebraska soils include loam, silt or clay in varying amounts, are low in organic matter and have a pH range of 6.0-7.5 or above. This poses a significant challenge to growing healthy, productive blueberries.
Providing an adequately low soil pH is the major obstacle to growth of blueberries in Nebraska. Plants grown in soil with high pH will have difficulty absorbing water and nutrients properly. The first symptom of a pH problem in blueberries is iron chlorosis, caused by a lack of iron in the plant. In most cases there is plenty of iron in the soil, but the high soil pH has changed the iron into a chemical form that plants cannot use. Symptoms include yellow leaves with green viens, usually seen on the youngest leaves first. In severe cases, the plant's leaves may become almost white, or have brown, scorched leaf edges. Affected plants are stunted with reduced fruit yield and will eventually die.
To try growing blueberries, start by having the soil tested in the planting area to determine the pH of the native soil. If the soil pH is not between 4.0-5.5 then work large quantities of such materials as peat moss, oak leaves, pine needles or sulfur into the area where the plants are to be set. This should be done 6 months to a year before planting, to allow the soil pH time to change. Retest the soil before planting to ensure the ideal pH level has been achieved. When using sulfur to acidify the soil, apply 3/4 lb. per 100 sq.ft. for sandy soils and 1.5-2 lbs. per 100 sq.ft. on heavier soils for each full point the soil tests above pH 4.5. Once proper acidity is established, the use of an acid fertilizer, such as ammonium sulfate, will help maintain this acidic pH.
Blueberries should be planted where they have full sunlight most of the day and far enough from the roots of trees to avoid competition for moisture and nutrients. They are shallow-rooted plants and must either be irrigated, heavily mulched or planted in a soil with a high water table. Adequate drainage must be provided, however, because they cannot tolerate wet feet. Mulching is the preferred soil management practice in the blueberry planting. The entire area around and between the plants should be mulched. Nearly any organic material is satisfactory, leaves, straw, hay, peat moss, crushed corncobs, wood chips or sawdust. Use of a pine needle mulch will again, help maintain the lower soil pH. It should be applied to a depth of 5-6 inches.
To provide adequate cross-pollination and to increase the chance for a good crop of fruit, two or more cultivars of blueberries should be planted. The following cultivars suggested for planting in home gardens in Nebraska, ripen over a 6 to 8 week period, beginning in July and continuing through August: Blueray, Bluecrop, Northblue, Northcountry and Northsky. All are vigorous and productive under good growing conditions and produce berries of large size and good quality.
Birds are a major pest when it comes to blueberries and the plants must be protected when the berries are nearing maturity to prevent them from stealing the entire harvest. Wire cages, netting or a remay cloth cover work well.
Growing Blueberries in Containers
Blueberries are a wonderful small fruit, which unfortunately do not grow well in most Nebraska soils. However, there is an alternative for the determined gardener willing to go the extra mile required to produce blueberries at home- blueberries grown in containers. Since soil pH is the major difficulty for blueberries in Nebraska, using containers can solve the problem. It is much easier to control the pH of soil in a container than it is to change the pH of soil in a ground bed. To grow well, blueberries require porous, moist, sandy soils high in organic matter with a pH range of 4.0-5.5. If the soil pH in the container is not between 4.0-5.5 then work large quantities of such materials as peat moss, oak leaves, pine needles or sulfur into the soil.
However, using a container to grow a woody, perennial plant that requires cold temperatures in the winter does present other challenges, though. Plant roots are much less cold hardy than plant shoots, and the roots of plants grown in containers tend to circle around the inside wall of the container. This can leave the plant's roots with only a thin layer of plastic for winter protection. Research in Oklahoma has shown the temperature of a root ball in an unprotected container can approach that of the surrounding air temperature. Therefore winter protection for containerized plants, both herbaceous and woody perennials, is essential to the plant's survival. Winter soil temperatures for containerized plants should stay in the 30-34° Fahrenheit range. Plant damage could result from temperatures lower than 32° .
There are several ways to provide winter protection for plants in containers. One of the easiest methods is to bring the containers into an unheated shed, root cellar or garage during the winter months. Of course, during the winter the plant still needs periodic watering and light. Water plants thoroughly before moving them into the overwintering area and periodically check soil moisture throughout the winter. It is important to inspect the plant periodically during winter to make sure it has not started to grow or send out new shoots. If this happens, the plant is being kept too warm and air temperatures around the plant should be lowered to stop the initiation of growth.
Another method of overwintering a containerized plant is to "plant" the entire container in a ground bed. In fall, dig a hole deep enough so that the lip of the container is even with the surrounding soil. Place the container in the hole and fill in with soil around the container just as you would with a new plant, so that the container receives full benefit of the soil's insulating power. The plant can then be mulched normally along with surrounding plants. It is also possible to install a second container, slightly larger than that used to hold the blueberry plant, permanently in the soil; again, bury the larger container deep enough so its lip is even with the surrounding soil. The blueberry container, with its properly amended soil, can then be placed inside the larger container and left in place all year or moved to a sunnier location during summer.
During summer, the containerized plant will dry out much more quickly than surrounding plants especially if the container is above ground. Frequent watering, thoroughly soaking the entire root ball, will be required to meet the plant's moisture needs, however do not let the plant sit in water.
Imagine the pleasure of harvesting blueberries from healthy plants in your own backyard. With some extra work, it can be done- but you'll have to beat the birds to the tasty berries!