Blueberries are sweet, highly nutritious and wildly trendy right now because they have the highest antioxidant capacity of all the popular fruits and vegetables; earning them the label “superfood.” They are also easy to grow if the correct soil conditions are met, are resilient against pests and diseases, and will provide you and your family with an abundance of fruit for many decades to come – so you really go can’t go wrong with blueberries.
The scientific name of those blueberries you purchased at the grocery store may not be important to you if you're making pancakes, but if you are planning to raise your own blueberry bushes, you’ll need to know what to look for; as some plants need other plants of the same species for successful pollination. Blueberries consist of many species in the genus Vaccinium of the family Ericaceae. The genus Vaccinium also includes cranberries, bilberries, and huckleberries.
Blueberries are native to North America, and for centuries Native Americans gathered them from forests and fields to eat fresh or to dry for later use. They called them “star berries” because of the perfect five-pointed star which forms at the blossom end of each berry. These hardy perennials are usually prostrate shrubs that can vary in size from 10 centimetres to 4 meters in height. Small but charming bell-shaped flowers appear in late winter or spring, and can be white, pale pink or red, and sometimes tinged with green. The berries are produced in summer, appearing pale green at first and turning to reddish-purple, and finally dark purple when fully ripe. They have a sweet taste when mature, with variable acidity; and are covered in a protective coating of powdery epicuticular wax, known as the "bloom." In autumn their leaves turn a fiery shade of red, before dropping.
In the commercial production of blueberries, the species with small, pea-sized berries growing on low-level bushes are known as the wild "lowbush blueberries" and the species with larger berries growing on taller cultivated bushes are known as "highbush blueberries." The highbush blueberry varieties were introduced into Europe during the 1930’s, where they now thrive; and in Ireland, baskets of blueberries are still offered to a sweetheart in commemoration of the original fertility festival of Lammas Day, celebrated on August 1. Lammas Day (Anglo-Saxon hlaf-mas, "loaf-mass") is a holiday celebrated in some English-speaking countries in the Northern Hemisphere, usually between 1 August and 1 September. It is a festival to mark the annual wheat harvest, and is the first harvest festival of the year.
Today many North American native species of blueberries are also grown commercially in the Southern Hemisphere, in South Africa, Australia, New Zealand, and South American nations.
In South Africa the blueberry industry is small relative to other domestic fruit industries such as citrus, apples, pears and table grapes, and 68% of our berries are grown in the Western Cape, with about 70% of the production being exported. However, the industry is growing rapidly due to domestic and international investments in the sector.
Uses:
In years gone by blueberries had a multitude of uses for mankind. Dried, they were added to stews, soups and meats; and crushed they were rubbed into meat for flavour. The juice was used to cure coughs, and tea made from the leaves of the blueberry plant was believed to be good for the blood. Blueberry juice was also used as a purple dye for cloth and baskets.
Today blueberries are sold fresh or frozen and are processed into fruit purée, or juice, and there is even a delicious blueberry wine. They are used fresh or dried in a variety of consumer goods, such as jellies, jams, blueberry pies, muffins, and breakfast cereals.
Health Benefits:
Blueberries are amongst the most nutrient dense berries, and a type of flavonoid called “anthocyanin” contributes to their numerous health benefits, and is also responsible for the berries characteristic blue colour. Blueberries consist of about 85% water, with an entire cup having only 84 calories, and 15 grams of carbohydrates. A single cup contains 24% of the RDA (Recommended Dietary Allowance) for vitamin C; 36% of the RDA for vitamin K; and 25% of the RDA for Manganese; plus 4 grams of fibre.
Blueberries have the highest antioxidant capacity of all the popular fruits and vegetables available today, and this is largely due to flavonoids which neutralize free radicals which damage your DNA; and studies have shown that blueberries do indeed protect the body from the damage caused by free radicals. Oxidative DNA damage is an unavoidable part of everyday life and occurs thousands and thousands of times every day, in every cell. It is the reason we grow older and plays a role in the development of diseases like cancer.
Blueberries are also fantastic for your heart and have been shown to reduce heart disease by preventing oxidative damage due to “bad” LDL cholesterol. Just 50 grams a day with a main meal can lower oxidation up to 27%.
Blueberries may be expensive, but for general good health they are worth their weight in gold, and well worth purchasing, even if it means you may have to forfeit your favourite dark chocolates to do so, and perhaps this is yet another excellent reason for you to grow your own!
Blueberry muffins. Picture courtesy congerdesign from PixabayIn the Kitchen:
Blueberries are one of the few truly blue foods on earth, and to harness their health benefits they are best eaten raw or in smoothies, but they can be lightly cooked in a pie or crumble, or used as a topping for various desserts such as pancakes, waffles and cheesecake. They go great with oatmeal and yogurt and are delicious in sweet breads and muffins. Because blueberries are one of the easiest fruits to freeze, if you’re harvesting your own, you could have them all winter long.
Cultivation and Harvesting:
At first blueberry growing might seem a bit technical, but this is not the case - by choosing the right blueberry bushes for your garden, amending your soil, and giving them a bit of routine care, you'll be able to enjoy the fruits of your labour for years to come.
Traditionally blueberries are known to grow best in areas with cold winters, because they need a fairly long “chill factor” during their winter dormancy period to bear well next season, and if temperatures are too warm, they simply won’t develop fruit. However, it is good to bear in mind that not all blueberry cultivars sold in South Africa are fully hardy, and even hardy cultivars can be damaged in winter if they are exposed to a combination of low temperatures and wet conditions, and especially if they are container grown. Because South Africa is so hot, USA breeds from the southern states like those in the Southern Highbush category seem to do best here, and many of the new cultivars used in the South African blueberry industry were developed in Australia from these USA breeds. These newer cultivars don’t require such a long cold dormancy period, enabling us to grow blueberries even in the milder sub-tropical regions along our coastline.
Most blueberry varieties sold at garden centres in South Africa are self-fertile and do not require another blueberry plant for cross pollination; and although it is not necessary, some of these self-fertile varieties will bear even better when they are cross-pollinated with another variety, and most sources suggest that it is always best to plant more than one variety. Although blueberries can be planted anytime, spring and autumn are best.
Generally, in South Africa we classify blueberry varieties into three groups; early season fruiting, mid-season fruiting, and late season fruiting. With these options, and depending on your region, it is possible to have fresh blueberries for 6 to 8 months of the year. To ensure you get the perfect varieties for cross-pollination, and for your growing region, visit a reputable garden centre for more advice.
There are many varieties of blueberries, but here are a few to consider:
'Misty' is a vigorous and upright plant which ripens in early to middle November and fruits heavily, but tends to leaf poorly. It requires a minimum of 200 hours of winter chill.
'O’Neal' has a semi-upright growth habit and produces large to medium-sized berries which ripen in late October to November. It requires a minimum of 400 to 500 hours of winter chill.
'Brightwell' is a vigorous, upright plant with medium-sized berries which ripen in December to early January. It requires a minimum of 350 to 400 hours of winter chill.
Although blueberries love full sun, be wary of our South African scorchers, our sunshine is stronger than these berries are used to. In hotter regions of the country site your bushes where they will receive some shade during the hottest time of the day, and during particularly hot periods, give them a little extra water to replenish them.
Like azaleas and rhododendrons, they require acid soil with a pH between 4 and 5, and if your soil is naturally acidic they can be planted directly into garden beds. If your garden has high-alkaline soil of 7.0 pH or higher, keeping pH low enough for blueberries can be difficult, and for this reason most gardeners opt to plant them into containers, where pH can easily be controlled. Tips from growers to maintain pH include using flowers of sulphur powder to make soil more acidic (available from Clicks or Dischem;) and to maintain a low PH level, either strictly use only rainwater, or in a pinch, add a dash of vinegar to tap water.
Whether you are planting into garden beds or pots, it is vital that the soil has perfect drainage, and is rich in organic matter. For potted specimens, select a large pot that is at least 40cm in diameter and provide ample drainage. Use a commercial potting mix designed for acid-loving plants, or mix equal parts compost, pre-moistened peat moss and topsoil. Earthworm castings are beneficial in encouraging the soil microorganisms that container grown blueberries need. Because commercial potting soil is normally slightly acidic, it can also be incorporated into beds or pots; and if drainage is not perfect, washed river sand can be included in the mix.
When transplanting the plant, make sure to plant it at the same depth it is growing in its pot, in order to ensure that the crown is not covered or the roots exposed. Blueberries love full sun but will take some dappled shade. Like azaleas and rhododendrons, they require acid soil with a pH between 4 and 5, and if your soil is naturally acidic they can be planted directly into garden beds. If your garden has high-alkaline soil of 7.0 pH or higher, keeping pH low enough for blueberries can be difficult, and for this reason most gardeners opt to plant them into containers, where pH can easily be controlled.
Whether you are planting into garden beds or pots, it is vital that the soil has perfect drainage, and is rich in organic matter. For potted specimens, select a large pot that is at least 40cm in diameter and provide ample drainage. Use a commercial potting mix designed for acid-loving plants, or mix equal parts compost, pre-moistened peat moss and topsoil. Earthworm castings are beneficial in encouraging the soil microorganisms that container grown blueberries need. Because commercial potting soil is normally slightly acidic, it can also be incorporated into beds or pots; and if drainage is not perfect, washed river sand can be included in the mix.
For the homeowner it is well worth investing in established plants which will produce a small crop of blueberries in less than one year. Because blueberries are long-lived, if you are planting several varieties in rows in the garden, ensure that your spacing is correct for the varieties you have selected. The popular southern highbush varieties which do well in South Africa generally grow +-1.2m tall with a spread of 1m. Blueberry plants can be planted as close as 60cm apart which will form a thick hedge after a couple of years, but in general most farmers fields are planted using a plant spacing of 0.9m to 1.2m between plants with spacing between rows of 1.8m to 2.8m which would result in a plant density of 3000 to 6200 plants per hectare. The distances between the rows will depend on which equipment will be used for cultivation, harvesting and pruning. With smaller scale operations hand harvesting is normally used where the row spacing’s are narrower.
Feeding blueberries need not be complicated and many gardeners give plants growing in the ground a single feeding in early spring with a fertiliser for acid-loving plants like azaleas, together with a good mulch of acid compost, and this should suffice if the soil is naturally acid. However, if your soil is not naturally acid, and your bushes are in containers, using acid soil, for the plants first year of growth in a container, a single application of fertiliser should suffice, but apply the fertiliser one month after planting, not at the time of planting. In the plants second season, the soil may have lost most of its acidity due to leaching out when watering, so feeding established container plants lightly every month or two will greatly increase their performance.
Blueberries certainly need nitrogen, but if you overfeed with nitrogen, you will have the most lush-looking plants in town, but sadly, very few fruits. Also, be careful not to use a fertiliser that contains nitrates, such as calcium nitrate or chloride, as some blueberry plants can be killed by nitrates. Organic gardeners use blood meal or fish meal to provide nitrogen; sphagnum peat or coffee grounds to provide acidity; and bone meal and powdered seaweed to provide the potassium and phosphorus.
Rain water is best for all plants, but especially for blueberries, so collect it in garbage bins or whatever you have handy, for watering your precious blueberries. Ensure that the plants receive regular watering in summer, especially during hot, dry spells, but ensure that they are not waterlogged. Potted plants should not stand continually in a drip tray full of water, or the roots will rot, so if you have to use a drip tray, cover the bottom with small pebbles, or use bricks to lift the bottom of the pot above the drip water line.
Blueberry Harvest Picture courtesy Tan Temmel from PixabayHarvesting:
Blueberries bear fruit in the end of their first year, but many gardeners prefer to remove the flowers to ensure a more vigorous plant for the following season. As the plant matures, the fruit starts clumping together and resembles grapes. Once mature, each plant can bear an average of 4.5 to 5kg of fruit. Don’t rush to pick the berries as soon as they turn blue, wait a couple days, and when they are ready, they should fall off right into your hand.
Pruning:
Pruning blueberries is very simple, and the aim is to prune only enough to allow more light to enter the inside of the bush, by cutting out any thin, weak stems, and those tiny branches and stems that are crossing each other. This light pruning can be done in autumn when the plants start going into their winter dormancy period. Wait until late winter to do any major pruning, when the plants are still dormant but their large buds stand out. Blueberries flower and bear fruit each year on wood grown the previous summer, and stems become unfruitful as they age. Each year, remove two or three of the oldest stems all the way to the ground, and prune back bud-less tips. Healthy stem tips can be pruned lightly, cutting about 6mm above healthy buds, using sharp bypass pruners for crisp, angled cuts.
Transplanting:
If you do need to transplant or repot your bushes it is best to do this during their dormant season, but transplanting during a hard frost is never advisable, so aim for early spring if you live in a harsher climate. In milder climates transplanting can be done in autumn or spring.
Propagation:
Blueberries start easily from cuttings taken from a mature, well-established plant, and will root in two to three months if they are treated with rooting hormone and are kept in a warm, moist environment.
Pests & Diseases:
If the correct soil conditions are met, blueberries are easy to grow, require little care, are resilient against pests and diseases.
Caution:
The information contained within this website is for educational purposes only, documenting the traditional uses of specific plants as recorded through history. Always seek advice from a medical practitioner before starting a home treatment programme.