What must an Illinois gardener know before planting blueberries.

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Blueberries require acidic soil. They prefer a pH of 4.8 to 5.2 which is below our average soil pH of 5.5 to 7.0. Get a soil test done to determine your pH and the soil testing company will send you recommendations on how to amend the soil. If the soil is not acidic enough the blueberry plants will not grow well and leaves may turn yellow. They may suggest elemental sulfur that is best applied in the fall. Ammonium sulfate can be used while the plants are growing to lower the soil pH. The rates for ammonium sulfate are one ounce per plant at time of planting, three ounces for two year old plants, eight ounces for four year old plantings and 12 ounces for eight years or older.

Illinois soils may be too heavy and amending he soil to improve drainage may be needed. The addition of organic matter or acidic peat moss may improve the tilth. Raised beds or large pots could also be an alternative to the drainage issue and keeping the soil acidic.

Blueberries need additional watering especially in drought. We usually recommend an inch per week but this estimate may increase to two to three inches if temperatures are high. Although blueberries require at least five hours of full sun some afternoon shade may be beneficial. Mulch is also a great strategy in conserving moisture for blueberry plants. Additional watering is essential because blueberry plants are shallow rooted therefore the roots do not mine the soil seeking out water and they may not produce adequate berries if they are lacking water.

Plant healthy plants in the spring that are known to do well in Illinois. The recommended spacing is four to six feet apart. Highbush cultivars 'Blueray,' and 'Jersey,' as well as hybrids (cross between high bush and low bush) 'Northland' or 'Patriot' are recommended for Illinois. High bush cultivars grows taller are a better adapted to our area than low bush types.

Blueberry plants need to be pruned during the dormant season in early spring. Prune diseased, broken, branches laying on the ground, or branches six years or older. Open the center of the bush but leave strongest canes behind. Blossom removal is recommended for the first two years after planting. The amount of blueberries harvested will grow as the plant gets older. Remember the canes that produce blueberries will be four to six years old.