How to Grow Series
If I had my way, blueberries would be in every backyard garden in America. In fact, they are suitable for front yard gardens as well. They have pretty white or pink blooms in spring and lovely red, orange or yellow foliage in fall. With lowbush, highbush, half-high and rabbiteye varieties, there is sure to be one that will grow in your climate.
Blueberries like full sun, well-drained, acidic soil that remains moist, although my husband swears he has picked blueberries in a swamp before. Because of the acidic soil requirement, it's best to grow blueberries away from other plants or near other acid loving plants like rhododendron or hydrangea. Choose varieties that ripen at different times to extend the harvest season. There are June, July and August bearing varieties.
Lowbush blueberries grow no more than 2' tall and make a great ground cover. Generally hardy between zones 3-6, they produce small flavorful berries. Many people grow lowbush varieties for the birds since the berries are so small.
Highbush blueberries are probably the most popular and are generally hardy from zones 4-10, though there are some varieties more suitable to warmer climates and some that are more suitable for colder climates. You will need to plant more than one variety to ensure pollination and proper fruiting. Highbush varieties tend to have larger berries and are very flavorful. Growing up to 8' tall, blueberries can make a nice hedge for privacy.
Half-High blueberries are hybrids of the Lowbush and Highbush varieties and are suitable for colder climates. Each are bred for size, flavor and disease resistance although they don't usually produce as many berries as the highbush variety.
Rabbiteye blueberries only grow in zones 7-9 and must be grown with two suitable varieties in order to set fruit. They grow upwards of 10' tall and have thicker skins making them better for travel.
Though blueberries can tolerate some shade, they will produce more berries in full sun (6-8 hours per day). Blueberries prefer moist soils that drain well and contain lots of organic matter, but they don't necessarily like a lot of fertilizer. Blueberries are best planted in early spring before they break dormancy, so prepare the soil the season before for optimum results. Till the soil, if you can, and incorporate compost, peat moss, composted pine mulch and/or sawdust into the top 6" of soil. Perform a soil test to determine soil pH. 4.5-5.0 is the ideal pH for blueberries. Sulfur can be added to the soil to help lower the pH. Follow the package instructions based on the results of your soil test.
Blueberries are best planted in late winter or early spring before they have broken dormancy. Bare-root plants should have their roots soaked for at least an hour in room temperature water before planting. Container grown plants can be placed in the ground at the same level they were grown in the pots. If your soil is full of clay, or if you are at all worried about it draining well (no standing water after two days), then it is recommended to plant the blueberries in hills to help facilitate drainage. Be sure to space the bushes appropriately depending on the variety you are planting. This could mean that the larger varieties are planted 6' apart.
Blueberries will not need pruning until the fourth year they are in the ground. Fruit buds should also be removed the first year (two years is ideal). After the bushes are established, you can begin to remove the oldest stems of each bush in late winter, before the plant begins to bud out for the season. Never remove more than a third of the plant at a time. You may also want to look for branches that might be crossing other branches and keep track of branches that didn't produce any berries the prior year. You can mark the stem with a little paint or loosely tie a string around any stem you want to cut later.
Blueberries do not like rich soils, so fertilizing often is not necessary. Applying a good quality compost around each plant in spring is generally all you will need to do. If you notice leaves turning yellow and drainage is good, your bushes may need some nitrogen and an adjustment in soil pH. It's best to fertilize with an organic fertilizer that won't burn the roots of the blueberries. Alfalfa meal is ideal and is available at most garden centers or feed stores. If you have trouble finding it, look for rabbit food that is pure alfalfa and mix that into the top inch or two of soil. Perform a soil test every two years and add sulfur around the plants as needed.
Harvesting & Storing
Blueberries are best picked a few days after they have turned blue. Look for berries that fall easily into your hand when you touch them. If there is any resistance at all, it's best to leave them another day. Blueberries freshly picked will last about a week in the fridge, though they taste better if they've never been cold. Since they are a powerhouse fruit full of nutrients and antioxidants, eating a cup a day will make you feel great! If birds are a problem, you can purchase netting to cover the bushes until the berries are ripe. Excess blueberries can also be dehydrated, frozen or turned into jams and jellies.