Tips on Growing Great Blueberries
If growing blueberries has you singing the blues, find out about new delicious varieties bred to bloom despite southern and coastal climate challenges.
One of the biggest nutritional powerhouses that you can eat comes in a very small package. Blueberries are packed with more cancer-fighting, anti-aging, eyesight-saving and disease-fighting antioxidants than foods like spinach and salmon. New plant varieties make growing blueberries even easier than before. Sure, they're the pie-inspiring, cereal-topping, muffin-mixing treat that can make your mouth water, but beloved blueberries are becoming a tasteful choice in another arena — the landscape.
Blueberries are typically grown in humid, northern climates that have winter chills, mild summers and low-pH or acidic soils, conditions that limit their range. But many new varieties are available for lower chill areas, very warm areas, as well as coastal areas. The blueberry now has an enormous range.
There are three main types of blueberries — low-bush, high-bush and rabbit-eye — all with fairly specific growing requirements. But thanks to the work of hybridizers, new crosses are much more forgiving.
"Southern high-bush are the new varieties," says expert Ed Laivo. These classic varieties are being introduced to the lower chill areas as well as the coastal areas and are also able to better tolerate heat. Many southern high-bushes are compact, meaning they're perfect for smaller yards or patios.
The trick to growing blueberries under less-than-desirable conditions (such as alkaline soils or warmer climates) is container planting. Pots give you a lot more control over the soil. Acidity is critical. "The nutrient uptake comes out of the soil, and a mix of peat, bark and an acid soil mix will help to provide everything the blueberry plant needs immediately after you plant it," Ed says.
His special blend for a low-pH soil is one part peat moss for acidity, one part bark (it's porous for good drainage, and as it breaks down, it adds organic matter to the soi,l which lowers the pH), one part acidic potting soil and a handful of soil sulfur. This is Ed's standard mix and it has a pH of about 5.5, which is right at the outside limit of what blueberries like for vigorous growth.
"If you're lucky enough to have a pH of between 4.5 and 5.5, then you can grow blueberries all day long," he says. "But most don't, so you really need to add an amendment that acidifies the soil." To do that, he suggests cottonseed meal or bloodmeal. To plant in containers, he transplants a two-gallon nursery plant into an 18-inch pot.
Blueberries like moisture because they're shallow-rooted, so the bigger the pot, the bigger the drink of water. Speaking of water, did you know the pH of water can vary enormously and affect the acidity and alkalinity of soil? Meters to measure pH levels as well as test soil kits are widely available to help with any necessary adjustments during the growing season.
Planting blueberries in the ground is different. The best way to plant a blueberry in the ground is to dig a hole about 2-1/2 feet wide and 1 foot deep. Ed also recommends removing the native soil. Use the same soil blend Ed used for the containers, but mix in native soil from the hole.
Many blueberries are self-fruiting, but for a bigger yield and a longer season, plant several varieties. Even in containers, high-density planting is the way to go. "The best way to get more blueberries is to plant a number of varieties so they cross-pollinate," Ed says. "More varieties means that you'll have an extended ripening period, which is always wonderful."
A healthy blueberry plant will fruit for 15 to 20 years before slowing down. Every five days or so, harvest the berries that are deep blue. "I always look for good dark color in the berry, and I think the darker the better," he says.
For the first three years, you won't need to prune young plants. After that, cutting the plant back once a year will increase vigor. Every winter, remove canes that are older than six years old and cut back all the other healthy canes by about a third. Remove any canes that have really tremendous amounts of discoloration, and remove all the lower, small, wimpy growth.
To protect your blueberries, drape a large piece of netting over some sort of framework such as bamboo sticks or an extra-large tomato cage.
Ed suggests planting blueberries as a shrub or as a screen. "You can use them as accent plants or as edible ornamentals." You can even plant them in containers and use them as patio decoration.