Crammed with antioxidants, they're good for you; their milder flavour is more palatable than currants; they prolong the soft fruit season; and they thrive in a pot, so they sit nicely on a patio.
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The health-giving properties of blueberries are worth repeating. The anthocyanins and antioxidants reputedly slow down or prevent the growth of tumours, lower blood pressure and help prevent obesity. Recent research at the University of Tufts in Massachusetts suggests blueberries could also slow down or even reverse memory loss in elderly people.
North American blueberries featured highly in the Native American diet. The women of the Iroquois tribe would cram their huge baskets with lots of different fruits, including blueberries, following the guiding principle: you ate a berry if it didn't make you sick. Settlers continued collecting wild blueberries until the early 20th century.
These wild fruits were the size of peas, so in 1910 two pioneers started domesticating the species, aiming to produce larger fruits. The botanist Frederick Coville, director of the US National Arboretum, and Elizabeth White, the daughter of a cranberry farmer, began by searching for bushes with larger berries. White offered fruit collectors a reward of $3 for identifying any bush producing berries with a diameter of "five-eighths of an inch", or about 1cm.
By 1916, 100 trees were found and Coville and White whittled them down to six, after eliminating those that had darker berries, were susceptible to disease and had bitter-tasting fruit. Over the next few decades, these scientists, along with other breeders, developed 75 new varieties.
Unfortunately, recent research has found that these cultivated varieties have lower nutrient levels than their wild progenitors. Weight for weight, smaller, darker berries contain higher levels of anthocyanins than larger ones. The variety Rubel is a clone of one of the original six varieties used by Coville and White. A recent study compared Rubel with 86 modern varieties and found it had the highest level of anthocyanins and the second highest amount of antioxidants. The variety is available from a tiny number of specialist nurseries in the UK.
Don't worry, though - all blueberries score well in antioxidant trials. Two of the higher-scoring varieties that are readily available are Blue Gold and Elliot.
Like all fruit, blueberries have their own distinctive flavour. They're slightly reminiscent of our native blaeberries - those tiny black moorland fruits that take forever to pick - but much larger and sweeter. I'm only too pleased to have them in the fruit cage at a time when autumn-fruiting rasps are the only alternative to soft fruit. And the berries hang on well into October.
In the right conditions, blueberries are easy to grow, either in the open ground or in a large container. The soil's pH is critical. The bushes require acidic ground, preferably with a pH of 4.5, but anything below 5.5 will do. If you live in the west, you'll probably be OK, but use a test kit to be sure. If, like me, you have neutral soil, a container might be the simplest choice, and you can use ericaceous compost. Alternatively, acidify the open ground by applying sulphur chips.
A three-year-old plant starts cropping well but needs rich, free-draining soil to do so. If you're using a pot then top dress every year, preferably with homemade compost, and change the compost every other year. An annual top dressing of compost in the open ground is also useful.
Blueberries also need to be well watered. Rainwater is best, as tap water can be more neutral. They produce a better yield if you grow more than one bush. Like all self-fertile plants, they benefit from cross pollination, and two plants could never be too many.