Growing Blueberries in the Home Garden - U of I Extension

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Growing Blueberries in the Home Garden

This article was originally published on March 1, 2011 and expired on May 31, 2011. It is provided here for archival purposes and may contain dated information.

The blueberry is a small fruit that is very popular among home gardeners, said a University of Illinois Extension horticulture educator.

"Growing blueberries can be very challenging and frustrating because they require specific soils and climatic conditions that may not be found in many parts of Illinois particularly the northern parts of the state," said Maurice Ogutu.

Blueberries require acidic soils with high organic matter content. They can be injured by late spring and early fall frosts and also mid winter temperatures below -20 degrees F. Blueberry plants are also expensive as the two or three-year old plants that are good for planting cost over $7 per plant.

"Blossom removal is recommended for the first two years after planting in order for the plants to channel energy into shoot and root development. Hence no crop for the first two years," he said. "The yield tends to be low during the third year after planting averaging about one-half pound per plant reaching peak of five pounds per plant in bushes that are more than six years after planting."

Home gardeners need to select right varieties, good location, amend the soil to the right pH, plant at the right spacing and depth, and care for blueberries until the berries are ready for harvesting.

Ogutu recommended the following tips:

  • Variety selection – Choose varieties that are adapted to your region and intended to use. Blueberries are self-fruitful (refers to pollen from same cultivar can pollinate flowers of same cultivar to form fruits) but planting two or more varieties that ripen at different times can extend the harvest season. Highbush types and hybrids such as Northland and Patriot (cross between lowbush and highbush types) are recommended for home gardens in Illinois, and for more information on other recommended varieties refer to this web site: http://urbanext.illinois.edu/fruit/blueberries.cfm?section=small.
  • Location – Plant blueberries on a site where they can get full sun that is at least six hours of direct sunlight in a day. Plant blueberries away from tall trees and shrubs. Plant on sloppy areas with good water and air drainage.
  • Soils - Blueberries require well-drained soil with acidic pH, and does well in sandy soils with high organic matter content. Test the soil and adjust pH to 4.5-5.2 range. If the pH is below 4.0 incorporate finely ground dolomitic limestone based on soil test results (about five to 10 lbs per 100 square feet). If the soil pH is above 5.2, add elemental sulfur to lower the pH and about 1-2 pounds of elemental sulfur is needed to lower the pH by one unit (such as from pH of 5.5 to 4.5). If the pH of established planting is slightly over 5.2, continued use of ammonium sulfate will eventually reduce it. Plant cover crops or add organic matter by incorporating peat, bark mulch or straw in the soil before planting.
  • Planting – Purchase 2- or 3- year old seedlings that are healthy and disease-free. Plant in early spring as soon as the ground can be worked. Plant four to six feet apart within the row and plant closer on less fertile soils. The rows are spaced 10 to 12 feet apart. Plant one to two inches deeper than they were grown in the nursery. Firm soil around the base of the plant and water immediately after planting.
  • Watering – Blueberries have fibrous root system and they are shallow rooted. Irrigate during dry weather using overhead or drip irrigation. Soak the soil to ensure that the roots within the 12 to 16 inch depth are watered.
  • Mulching – Use organic mulches such as sawdust, bark, wood chips, straw or leaves. Spread the mulch six to eight inches thick around the base of the bushes to control weeds and conserve moisture. The nitrogen fertilizer requirements in mulched plantings may be two to three times higher so the amounts applied needs to be adjusted.
  • Fertilizing – One week after planting apply one ounce of a magnesium containing fertilizer such as 20-0-10+5 (N-P-K-Mg) in a band within 12 to 18 inches from the base of the plant. In established plantings, apply ammonium sulfate every year just before growth resumes in early spring to supply nitrogen based on the age of the planting. The ammonium sulfate requirements will be met as follows: three ounces for two year old planting, eight ounces for four old planting, and 12 ounces for eight or more years old planting.
  • Weed control – Control perennial weeds before planting. Control weeds that emerge during the first year after planting by cultivation. Avoid root injury by cultivating no deeper than one to two inches as blueberries are shallow rooted. Put mulch around the base of the plants to control weeds. Herbicides can be used for weed control but remember to read directions on the label before purchasing or applying any pesticide.
  • Pruning – Blueberry bushes are best pruned when dormant in early spring. Young bushes require less pruning during the first three years. Prune young bushes by removing damaged branches and spindly growth around the base of the plants. Mature bushes are pruned annually and the most fruitful canes are four to six years old. Remove damaged or diseased canes, remove spindly canes or canes lying on the ground, and canes that are more than six years old. Open the center of the bush by pruning overcrowded canes.
  • Pollination – Although blueberries are self-fruitful, higher production had been reported where two or more different varieties are planted in the same patch. Blueberries require bees for pollination. Cold weather or rainy or windy conditions can slow bee activity and may lead to poor fruit set. Do not spray insecticides when plants are in full bloom.
  • Harvesting – Protect mature fruits from birds by covering with nets. Blueberries may require two to four pickings as the fruits ripen over several weeks. Pick only fully ripe berries. Hand pick by gently rolling the berries between your thumb and forefinger. Place fruit gently into pint containers, cover the containers and refrigerate at 55 degrees F.

Source: Maurice Ogutu, Extension Educator, Local Food Systems and Small Farms, ogutu@illinois.edu

Pull date: May 31, 2011