Small Fruits & Berries 101
The most popular berries among gardeners are the same ones that still come to market: strawberries, blueberries and, occasionally, red raspberries. We grow what we know, naturally enough. But why stop with only those? With a few more bush and bramble berries, you can have a steady supply of fruit all summer long. A gooseberry bush or two will fill the gap between the last strawberries and the first raspberries and still be ripening fruit when the raspberries have finished. Midsummer brings on the red and white currants and blackcap raspberries. After that come the blackberries and then blueberries, and finally the late red raspberries, which ripen until frost. Compared with apples, peaches or any of the tree fruits, bush and bramble fruits are easy to grow. They rarely require spraying for pests and begin bearing some fruit the year after you plant them. By their third season they should be in full production. Perhaps most important, they're very space efficient. None require a mix of varieties for cross-pollination.
With intensive culture, berries will reward you handsomely. First aim for variety and a long harvest season, then plant small numbers of each kind and care for them well. Buy the smallest number of plants you can as you're learning, and if you want more, get a second variety.
Incorporate lots of organic matter before planting, and mulch with shredded leaves or compost every year. Prune regularly through the season to keep each branch or cane as productive as possible. And train the bushes and brambles against walls and fences to make better use of space. Here are some thoughts on the major classes of berries and how to fit them into your garden space.
These are the first fruit of the season, which may be why people treasure them so. Since your fruit garden will provide you with a variety of other berries all season long, forego everbearing strawberries in favor of main croppers. An early and a late variety will provide strawberries for two to three weeks. Consider old standards, such as 'Fairfax' or 'Sparkle', that are so soft they leave your fingers red with juice after picking.
Renew the planting every year by tilling or digging under most of the plants and letting runners set in well-worked, fertile ground. Keep them in a bed to themselves, however, since strawberries are susceptible to verticillium wilt carried by tomatoes, peppers, eggplant and potatoes. Use wire arches over the beds (the kind you'd use for plastic tunnels) to support bird netting.
Gooseberries grow on dense bushes that reach two to four feet tall without training. They're hardy throughout most of the U.S. excepting the southwestern deserts and the inland valleys of California. Best fruit production occurs in the mid-Atlantic and northeastern U.S.
Gooseberries leaf out early in spring. The foliage is a lustrous green, turning bronze to red in fall, and branches are covered with straight, inch-long spines. The ripe fruit is either translucent yellow-green or dusky purple to red, depending on the variety. When ripe, the fruit is juicy and sweet with a pleasing acidity. As with any fruit, there are marked varietal differences in flavor.
Gooseberries are one of the few fruits that hold their quality well on the bush when ripe. The earliest gooseberries (which can be picked green) fill the brief gap between the last strawberries and the first red raspberries. When the berries reach about 1/2-inch diameter and are still hard and a month from being ripe, they're excellent for pies and other cooked desserts. This early harvest thins the fruit so the ripe berries will be larger.
Gooseberries, especially the unripe fruit, are high in pectin; you can make very thick jam with no added pectin. A mature plant can produce from five to eight quarts of fruit, so one plant may be all you need. Where space is extremely limited, train gooseberries against walls as fan-shaped espaliers or as single-stemmed cordons. These make striking plants with year-round interest, and picking will be easier, too.
Gooseberries bear fruit near the base of one-year-old shoots and on short spurs on older wood. So no matter how carelessly one prunes, there's always some fruit. Remove about 20 percent of the oldest growth--wood that's been growing for three to five seasons--each year. Also cut out enough of the newest growth to make the plant open and easy to pick. Always save some vigorous new shoots to become future main branches. Any new shoot can be cut back to four to six inches with little loss in fruiting potential.
A 30-foot row of raspberries, trained to single stems against a wall or fence, will yield about a quart of fruit every other day for three weeks, and that's plenty of raspberries for most people. A more traditional hedge-type planting will yield twice that amount, although it takes at least twice the space. Intensively trained berries are extremely productive. To get the most from red raspberries, plant at least two kinds: a main crop variety for heavy early summer harvests and a fall (or everbearing) type to close out the berry harvest. Where the season is long, you may need to plant two fall varieties to keep you picking until frost.
The popular 'Heritage' variety, for example, will be finished in early September in USDA Zone 6, with about four weeks of potential ripening weather left. It's a mistake to cut raspberry canes back in an effort to make the canes self-supporting. The most fruitful buds are those nearest the top of the canes. You'll get the best results by tying the canes to two wires 2-1/2 and five or six feet off the ground, depending on the vigor of the variety. Main-crop raspberries fruit on one-year-old canes. After harvest, cut them out at ground level to favor the new canes. When you've got vigorous new canes growing about six inches apart, remove any new ones that appear through the growing season. Fall raspberries fruit on new canes at the end of their first growing season and again the following summer. For heavier fall crops, prune the canes to the ground after the first harvest in autumn and forego the summer crop from fall varieties.
Although closely related to the reds, blackcaps have a distinctive flavor, ripen a little later, and require slightly different training. Black raspberries spread by bending the tips of their canes to the ground where they root, leapfrogging along at two to three feet a year. New shoots arise only from the original crowns, not willy-nilly from the roots as with reds. In most other respects, they're very similar to the reds. There are no fall-fruiting black raspberries. In an attempt to bend to the ground and root, the canes elongate and become thin and weak at the tips. Unless you want to start new plants, cut these raspberries back to 3 or 4 feet. They'll be self-supporting, with no loss of fruiting potential. Cut the old canes out after harvest. Since black raspberries don't throw root suckers, they take much less thinning than reds.
Currants: Black, White, and Red
Judging by flavor alone, most people would regard currants as two totally different fruits: the fresh, tart, and crystalline reds and whites versus the strangely pungent and heavy blacks. But they're close botanical relatives, and because they ripen about the same time and their culture is almost identical, it's best to consider them together.
Red currants are one of the most beautiful fruits. When the berries are ripe, the plant literally drips with long clusters of gleaming scarlet beads. Each red berry (white currants are just different varieties of the red currant) has a transparent skin, so sunlight makes it glow from within. Currants are very juicy and quite tart. When fully ripe, they are enjoyable out of hand the way you would eat any other berry. Traditionally, currants are used for jelly, jam, and cooked desserts. Ripe currants will hold on the bush for much longer than most other fruits without dropping or losing quality.
Black currant bushes are slightly larger than red currants, and the fruits are not so conspicuous. Black currants are meatier, less juicy, and eaten fresh they're definitely an acquired taste. Cooked, however, they lose their musky overtones and make one of the finest flavored jams of all.
Blackberry culture began in North America, although there are fine-flavored species native to Europe and Asia. Today's improved varieties have mixed heritage, part American natives and part Eurasian species. Blackberries are far and away the heaviest bearing of the bramble fruits, producing about twice as much as red raspberries. They ripen in mid-summer after the raspberries are finished, and are more heat tolerant than raspberries.
Blackberries are robust plants that need to be restrained or they can become weeds. They grow and can be trained very much like red raspberries. However, since they throw root suckers so vigorously, you may want to confine their roots with metal or fiberglass barriers sunk a foot or more below ground level. Blackberries are much more thorny than reds or blackcaps. Where space is restricted, or if you don't have the patience to pick a prickly plant, choose the new thornless varieties. Many of these are limber-stemmed and trailing in habit, so you'll need to rig a wire trellis to train them up.
Blueberries are really a new fruit, domesticated only within the last 75 years. They probably would have been tamed sooner if people had understood their need for an acid soil. Brought from the American wilds into gardens, the fruits almost always died because the soil had been limed. Blueberries demand a soil pH between 4.0 and 5.5. Correct the pH for blueberries with peat moss (mixed at least 50/50 with your native earth) and perhaps some soil sulfur, and the plants will do well over most of North America. The bushes have extremely shallow root systems, so the heavy peat blend need not be deeper than 12 inches. Blueberries need a steady supply of moisture; the water-retentive peat will help with that as well.
One blueberry bush is all you need. In its fourth season it will produce a pint or so of fruit. At maturity, when it's grown four to six feet tall, the right variety can produce up to 20 pints over two to three weeks. However, if you've room for three or four varieties, you can stretch the harvest to eight to 10 weeks, into the fall raspberry season. Although cross-pollination isn't essential, it will encourage larger fruit. Blueberries are extremely handsome shrubs, notable for their brilliant fall color and bright stems in winter. Some of the newer varieties are low and shrubby, 18 to 24 inches tall. Keep them away from masonry walls and foundations, where the soil can be excessively alkaline. But they're excellent among other ornamental shrubs (if the soil's suitable) or by themselves in an informal hedge. When a branch stops producing fat flower buds in fall, it's time to cut it out at ground level. That's all the pruning blueberries need.