I’ve never had much appetite for blue food. Apart from the sky, blue is rare in nature, and even more so on the plate.
A delphinium blossom or a huge, iridescent Morpho butterfly are both miracles of blueness. But I pass up those Peruvian blue potatoes in favor of golden ones, and the same goes for blue corn chips. I regard turquoise M & Ms as a big mistake. Maybe it’s because blue is the color all food becomes if it sits around too long.
The one crowning exception is the blueberry. Light or medium blue on the bush, deep blue in a pie, this native fruit is one we’ve all grown up with, especially in Maine, and when that pie has been eaten we wear our blue smiles proudly.
We now know what that color is all about. Among a number of studies demonstrating blueberries’ high nutritional value is one by the USDA Human Nutrition Research Center on Aging at Tufts University. It ranked some 40 fruits and vegetables for antioxidant activity — a process that protects the body against aging, environmental toxins and disease. The study put blueberries squarely at the top. It’s thought that blue-purple anthocyanins are the source of this power.
Since blueberries are delicious, and a magic health potion to boot, I can’t imagine not having at least a few bushes around to ensure a yearly crop, and frankly I’d grow them even if I had no reason to eat the fruit. They’re handsome, long-lived shrubs, too long ignored as ornamentals and taken for granted like so many of our natives.
The white flowers, if not dazzling, are pretty, and the fall foliage a spectacular red, orange or gold. Most cultivated varieties are a convenient 3 to 7 feet tall. Since they like moisture they’re perfect for a pondside planting. They also make a fine informal hedge, combining well with other bird-friendly shrubs like winterberry and viburnum, or in a border of acid loving plants like mountain laurel and rhododendrons. You can even grow them in pots.
The two important things blueberries need are consistent moisture and acid soil. In the wild the high-bush type are often found in swamps, not sitting with their roots in the swamp but perched on hummocks at least 14 inches above the water table. They have shallow, fibrous roots, which lack the root hairs by which other plants adjust to a range of moisture conditions.
In your garden they’ll require good drainage and some irrigating in dry weather, especially when fruiting in early summer, or in late summer when they set the fruit buds for next year. Lowbush blueberry, a northern species, and the towering rabbiteye blueberry, a southern one, are both more drought-proof.
The perfect pH for blueberries is between 4.2 and 4.8, and if your soil is very alkaline, or is heavy clay, they may not be the crop for you. But you can acidify a neutral soil by adding organic matter such as peat moss and composted pine bark. Organic matter also helps the soil to retain moisture and allow excess to drain. A sawdust, bark or pine needle mulch is helpful. Avoid both lime and wood ashes, which are alkaline. Blueberries need little fertilizing, but a top-dressing of cottonseed meal and will give them a boost.
If your chosen site needs some work, it would be best to prepare it this summer, let the soil mellow, then set out the plants early next spring. Give new plants lots of water, and prune off the fat fruiting buds the first year, to promote vigorous growth. Any good local nursery can supply you with a selection of early, midseason and late varieties for a long harvest. Planting several different ones will also insure cross-pollination, and hence bigger, more numerous berries. Most high-bush blueberries will thrive in the region, although the most productive one in our yard is named Berkeley.
The fruits are at their peak of flavor and potency after they have been thoroughly blue for several days. Birds know this too. Some people put netting over their bushes — I prefer just to plant enough for everybody. The berries are ripe when they just fall into your hand or bucket when touched. To freeze some for year-round eating, spread them in a single layer on a rimmed cookie sheet. When they’re frozen hard, collect them into plastic bags. This keeps them nicely separated, and you can do it a little at a time, as they ripen.
The harvest starts in June with early varieties like Duke and Earliblue. There will be a feast of blueberry pancakes, blueberry cobbler, blueberries to sprinkle on cereal, ice cream and cottage cheese. Blueberries to bake into muffins. Blueberries in jam, syrup and sauce. How about in bread pudding? Sounds great. In milk custard? Maybe not. That might be just a little bit too blue.