Ornamental shrubs enhance a landscape with their textures and colours, season after season, and blueberries can work similar wonders in an edible landscape. Native to moist, acid soils in North America, various types of blueberries have been improved to the point where some type of blueberry can be grown in almost any garden. In addition to producing delicious berries that can make you healthier and smarter, blueberries look good in every season of the year. Spring flowers give way to clusters of purple berries in summer, and the leaves turn bright red in the fall. In late winter, the twigs often turn shades of red and purple, bringing subtle colour to a snow-covered garden.
2009 was a banner year for blueberries in the UK, where sales of locally-grown blueberries tripled due to an abundant supply. Most of the varieties grown in the UK bear pedigrees from public breeding stations in the US, for example early-bearing ‘Duke’ and cold-tolerant ‘Elliott’. These (and many other varieties) are called northern highbush blueberries, descended from strains that grow wild in the eastern mountains. This group of blueberries is generally rated as adapted in Zones 5 to 7, or where the lowest temperatures of winter range between 5°F(-15°C) and -20°F (-28°C).
If you live in a colder climate, you can still grow great blueberries by looking to what are called "half high" or northern lowbush blueberries. Northern lowbush varieties like ‘Northland’ and ‘Patriot’ are not as productive as the highbush types, but they can withstand much colder temperatures, to about -40°F (-39°C).
Heat tolerant blueberries for mild winter climates are easily found among rabbiteye blueberries, which produce bumper crops in Zones 7 to 9. In warm, humid climates, rabbiteye blueberries are often among the easiest fruits to grow organically.
Blueberries’ Basic Needs
Assuming you have chosen compatible cultivars that suit your climate, it will be important to station them close to one another so that small pollinating insects will carry pollen between the bushes. Most cultivated varieties are self fertile, but pollination is often better (and the harvest season is longer) when two or three different varieties are grown. Plants spaced 3 feet (1 meter) apart in the garden will grow into a head-high hedge, or you can station two or three plants together in a sunny corner. Many varieties also can be grown in large containers, which is the best way to grow blueberries if you have neutral or alkaline soil. Blueberries cannot take up nutrients will unless the pH is quite acidic, below 5.5, so most gardeners need to amend planting soil with leaf mould, garden waste compost, or other acidic amendments to grow good blueberries. Light dustings of garden sulphur will also keep the pH down in the blueberry patch, as will acidic mulches like pine needles, rotted wood chips or sawdust.
Blueberries also need plenty of moisture but not too much. They benefit from a generous surface mulch that keeps the shallow roots from running dry. Plan ahead to use soaker hoses or another efficient watering method to provide water to plants during droughts.
Well-sited blueberry bushes can produce heavy crops for decades, but it often takes 3 years or more for young plants to start producing. To help them grow fast yet sturdy, most people pick off any fruit that is produced in the first two years after planting.
With mature blueberries in your yard, your biggest challenge will be to wait until the fruits turn fully ripe to eat them. It’s hard to wait, but I find that the berries’ flavour improves for several days after the berries turn from green to dark blue. Most plants bear for at least a month, which gives us plenty of time to stash them in the freezer for making pies and preserves. In 2008 (a banner blueberry year in the US), we even made a small batch of blueberry wine. It’s pretty darn good!
By Barbara Pleasant