Delicious and Decorative Blueberries

Blueberries, probably more than any other of the berry fruits, make spectacular landscape plants. They will team happily, either on their own or in groups, among other shrubs or perennials in the garden, providing colour and contrast in every season. In winter they offer intricately branched bare bushes with grey old wood and twiggy new growth of green, yellow and red. Then come the fresh green leaves and profusion of small, bell-shaped white flowers in spring. As summer progresses, the swelling fruit turns from green through shades of blue, purple and sometimes almost black. You eat the fruit, and then enjoy the brilliant red, orange and yellow foliage in the fall. The blueberry is truly a plant for all seasons.

So Many Cultivars

I described some of these in “Best Berry Bets,” GardenWise, Spring 2004, where I counselled growing more than one cultivar. Even though modern-day blueberry cultivars are partially self-fertile, fruit set is usually improved by having two or more cultivars. One of these probably should be ‘Bluecrop’, which is still the best known and one of the most reliable cultivars in the world. Others recommended include ‘Earliblue’, ‘Duke’, ‘Spartan’, ‘Reka’, ‘Polaris’ and ‘Patriot’, all of which are earlier ripening than ‘Bluecrop’. Those like ‘Bluecrop’, that ripen in mid-season, include ‘Northland’, ‘Hardyblue’, ‘Chippewa’ and ‘Blueray’. If you want to enjoy fresh berries well into September, grow a bush of ‘Elliott’. It is also worth checking with your local garden centre to see if new cultivars are available and what advantages these might have.

Care, Cultivation & Cold Tolerance

While blueberries are well-suited to the mild maritime climate of the Pacific Northwest, cultivars such as ‘Bluetta,’ ‘Northblue’ and ‘Northsky’ are hardy to zone 3 and do well in colder interior regions. ‘Northland’ is hardy to zone 2 with flexible branches that bend under heavy snow loads. Like rhododendrons, azaleas, heathers and other members of the heath family (Ericaceae), plants flourish in well-drained acidic soils with pH values between 4.5 and 5.2, high organic matter and an even moisture supply.

It is important to use only certified stock obtained from reputable garden centres. Plants must be free of canker, crown gall and viruses. Two- or three-year-old plants, bare-rooted or in containers, are best for quick establishment and production. You can use one-year-old root cuttings, but expect to wait longer for berries.

Prior to planting, dig well-rotted compost or manure into the soil. Planting can be done in autumn or early spring, though spring is best in colder regions to avoid losses due to frost heaving. With container-grown plants, gently loosen the root ball to stimulate development of fibrous root systems. Space the more vigorous cultivars .9 to 1.5 m (3 to 5 ft.) apart. If you plant in autumn, prune plants in early spring; if you plant in spring, prune immediately. Cut the branches back to about 30 cm (1 ft.).

Mulching helps maintain soil moisture at a constant level. Commercial plantings often use sawdust, but as it breaks down, it can cause nitrogen deficiencies that will need to be remedied with appropriate fertilizers. Black plastic, which conserves moisture and suppresses weed growth, is a better bet in your garden. Plastic is laid down at the time of planting and usually needs to be replaced every few years. If your garden has a heavier soil type, I suggest beds raised as high as 30 cm (1 ft.) to improve drainage during the fall and winter months.

Annual pruning helps maintain yields and fruit size and control disease and insect pests. I have seen bushes 3 metres (10 ft.) high, but for easy picking it is best to keep them under 2 metres (6.5 ft.). Anytime in the dormant season, from late December through to mid-March, remove weak, old and diseased canes from ground level. This encourages an abundance of vigorous one-year-old wood for fruit production. The root system is fibrous and shallow and thus any weeding is best done by hand to prevent damage. Productive plantings benefit from the addition of well-rotted compost each spring.

Keeping a vigorous, open bush minimizes damage caused by insects or diseases. Mummy berry, caused by a fungus with the rather impressive name Monolinia vaccinii-corymbosi, is sometimes a problem but removal and destruction of dried-up, wizened berries will help control it. Raking up and removing leaf debris also helps control diseases. Try to avoid the use of chemical sprays, so predator insects will build up and help control aphids and other pests.

Birds like the ripening blueberry fruits as much as we do. If you have just a few bushes, the best bet for protection from our feathered friends is draping nylon or plastic netting over the bushes when fruit starts to ripen.

Can any gardener resist a sweet, plump blueberry ripened to perfection under a warm summer sun? Unlike most berries, the fruits keep for days, not losing their irresistible flavour or showing signs of rot. And fresh blueberries are available during the winter months when they come to us via air from southern hemisphere countries, like Chile and New Zealand. Of course, you can easily freeze ripe fruits picked during the summer from your own bushes and open the packages throughout the winter months for instant, healthy snacks – much better than candy. Blueberries, either fresh or frozen, are ideal for muffins, cheesecakes, pies, jam, juice and syrup; in recent years, they have been used to make wine and cider.

We like blueberries because they taste so good, but they are also good for us. The berries are high in anthocyanins, which are responsible for the blue-purple colour and are sources of antioxidants. This group of chemicals protects the body against damage from oxidative stress, one of several biological processes implicated in aging and in the development of neurodegenerative disease. Eating blueberries on a regular basis helps improve memory and eyesight. And who among us does not need these improved? Hear, hear!!!

Hugh Daubeny is a research scientist emeritus with Agricultural Canada’s Pacific Agricultural Research Centre, where he spent 35 years developing strawberry and raspberry breeding programs.