If you are from a region of the country where blackberries grow wild, the mention of sun-ripened blackberries may stir memories of wild-blackberry-gathering expeditions, of warm summer days, walks through the woods and the inevitable purpled fingers.
Although there are not many wild blackberry patches in the Southland, most of Southern California is prime growing area for the olallieberry, a magnificent large blackberry with a flavor that rivals its cousin. (Blackberries, incidentally, are one of nature’s healthier foods, containing generous amounts of vitamins A and C and rich in potassium and fiber.)
Because they don’t ship well, olallie and other blackberries are seldom available in local markets, and if you do find them, they can be outrageously expensive. But if you have a 5-by-18-foot space in your yard, you can grow up to 15 gallons of berries yourself.
Bare-root olallieberry plants are becoming more common in local nurseries and garden centers during our bare-root season--mid-December to early March.
Choose a long, narrow and sunny area for your olallieberry patch, which should take two years to establish. The berries are produced on plants whose roots and crowns are perennial and will live for many years.
However, the thorny canes (stems) that rise from the crowns are biennial and live for only two years. During the first year these canes produce laterals (side branches) but no fruit. During the second year, small branches emerge from buds on the laterals and produce fruit.
Olallieberries should be trained on a trellis. The soil should be prepared in the same manner you would a vegetable or flower garden. It should be well-cultivated and enriched with organic materials and a light application of fruit or vegetable fertilizer.
Before you set the plants in the ground, cut the tops of the canes back to six inches. Make a planting hole in moist soil and place the roots at about the same depth they were in the nursery containers. Firm the soil around the plants.
Train the plants on a six-foot trellis and space the plants 2 1/2 feet apart. The trellis can be made of 2-by-4s with a 1-by-2 running across the top. Three strands of clothesline wire should be spaced at equal distances underneath.
During the first season, train the canes to sprawl over the trellis. The plants go dormant in winter; the next January you cut off all but six canes from each plant and train them to your trellis. Cut the tips so that each cane just reaches the trellis top. Fan them out and tie them along the wires.
Each cane will have a number of laterals, which produces the berries. Around the first of February, prune these side branches to 12 inches in length to increase the size of the fruit.
The second year should produce a good crop of fruit. Also during the second year, a new growth of canes will appear that may be trained along the trellis or allowed to sprawl on the ground.
After harvest, cut off all the old canes that have produced fruit. These will not bear again and will drain the plant’s energies if not removed. Repeat the pruning and training process each January.
Olallieberries should be watered weekly during the growing season. Fertilize plants the first year in mid-summer, and in each succeeding year apply fertilizer in early spring when foliage growth begins and again in mid-summer.
A 10-10-10 or similar fertilizer applied at two pounds per 18-foot row will supply nutrient needs. Weed your olallieberry patch regularly, and remove sucker growth.
The berries will begin ripening in mid-May and continue for a month or more.