Blueberries lack abundant root hairs and have shallow, underdeveloped roots concentrated in the top 14 in. of soil. As a result, regular watering and thick mulch are critical to keep the weeds down. A very acid pH is necessary for the plant to extract iron and nitrogen from the soil. Most blueberry problems are caused by stress related to pH, either under- or overfertilization, or under- or overwatering. Plant 2-year-old bushes. When your plants arrive, do not put them in water. Follow directions and "heel in" until ready to plant. Try inoculating the roots with the beneficial mycorrhizal fungi, which increases yields significantly. Lowbush varieties are grown primarily in New England, highbush throughout the nation, and rabbiteye only in the South and West. Lowbush and rabbiteye require another variety for cross-pollination; highbush types don't, but yields increase with cross-pollination. To encourage root growth, remove all blossoms for a full 2-3 years. The delayed harvest will pay you back in higher yields and healthier plants. Blueberries mature about 50-60 days from pollination. For areas prone to late spring frosts, blueberries are a good choice, with strong frost resistance. Consider adding blueberries to your landscape as beautiful ornamentals.
Leave berries on the bush 5-10 days after they turn blue. They're fully ripe when slightly soft, come off the bush easily, and are sweet. Pick directly into the storage bowl or container so that as little as possible of their protective wax is removed.
Don't wash the fruit if you're going to freeze it. Fresh blueberries can be stored in refrigerator for 7 days.
Height - Lowbush: 2-4 ft. Highbush:5-6 ft.
Spacing - Lowbush: 3-4 ft. Highbush: 7-8 ft.
Rows - 10 ft.
Root Depth - Very shallow, top 14 in. of soil.
pH - 4.0-5.6
Bearing Age - 3-8 years
Pollination - All varieties require cross-pollination.
Chilling Requirements - Low and Highbush: 650-800 hours below 45°F. Rabbiteye: 200 hours.
Site - Full sun; choose a site where plants won't be disturbed, away from paths, roads and driveways.
Water - Heavy and evenly moist.
Mulch - 3-4 in. acid mulches such as pine needles, peat moss, shredded oak leaves, or rotted sawdust.
Fertilizer - Apply 1 in. of compost under mulch. Avoid high N, aluminum sulphate, or urea. If you must apply ammonium sulphate, use 1/2 ounce in year 1, and 1 ounce for every additional year thereafter.
Pruning - Don't prune until the third year after planting because blueberries fruit near the tips of 2-year and older branches. To prune, cut out diseased tips and, for larger fruit, cut branches to where buds are widely spaced. Also cut out weak and diseased branches or canes, as they are called by commercial growers. Every 2 or 3 years you may need to cut the 5-year or older canes back to the main stem. Don't leave any stubs because suckers will be weaker than the new canes growing from the roots. A good rule of thumb is to allow one branch per year of age plus one or two vigorous new branches. If new branch growth on an old bush (15 years) is thinner than 1/4 in., cut out half of the new canes.
Blueberry Pests & Diseases
Apple maggot, birds, cherry fruitworm, fruit fly, mite, plum curculio, weevil.
Bacterial canker, cane gall, mummy berry, Phytophthera cinnomomi, powdery mildew. Many problems are due to lack of acidity.