It’s almost blackberry picking time! Blackberries ripen in late May and early June. Blackberries need to be harvested when fully ripe because they do not ripen after harvest. Usually a cultivar bears fruit for 2–4 weeks. Refrigerate berries as soon as possible after harvest and do not let harvested fruit sit in the sun. Blackberries can be used in blackberry cobbler, blackberry buckle, cake, pies, tarts, jam, jelly, and syrup. You can also put them in smoothies and slushies. Blackberries may be canned, dried and frozen. If you’d like to grow your own, blackberries can tolerate many soil types but grow best in full sun and well-drained soil. The most suitable soils are high in organic matter and have a pH of 6.0–6.5. Sandy loam or loam soils are best. Blackberries can be grown on sandy soils if a good irrigation system is used. In general, their root systems do not tolerate wet soils. Avoid clayey, poorly drained soils. Raised beds are recommended for locations with poorly drained soils or in areas prone to flooding. Establish blackberries in late February or early March by planting plants or root cuttings. Container-grown blackberry plants are more expensive, but these will also grow well. Root cuttings are collected from healthy plants during the dormant season. Note that it is illegal to propagate some cultivars that have plant patent protection. They should be 4–7 inches long and one-eighth to one-half-inch thick (about the size of a pencil). Space the root cuttings or plants 2 feet apart within rows that are 10–12 feet apart to form a hedgerow. Place the root cuttings 1–2 inches deep in well-prepared soil. Fertilize the plants 1 month after planting with 10-10-10 or 13-13-13 and again in late June (using 5.5 pounds per 100 feet of row in a 2-foot band). Increase the fertilizer rate the next year to 11.5 pounds per 100 feet of row applied in February and 5.5 pounds per 100 feet in June. Spread the fertilizer evenly over a 2-foot band. In following years, use 11 pounds of fertilizer per 100 feet in March and 5.5 pounds of fertilizer per 100 feet of row immediately after harvest, evenly applied over a 3-foot band. In the first growing season, canes from erect blackberries will be semi-erect or almost trailing In the first growing season, canes from erect blackberries will be semi-erect or almost trailing. Keep them within the row area since they will produce fruit the next year. New canes produced in the second and later years will be erect and need to be topped at 3–4 feet in June to encourage lateral branching. Vigorous plants may require topping two to four times. Prune hedgerows to a width of 3–4 feet. Blackberry canes are biennial. Vegetative canes develop the first year, bear fruit the second year, and die after fruiting. Fruiting canes must be removed after harvest. New canes from the roots will replace these canes. The new canes will have fruit the following year. For more information, go to extension.msstate.edu and search Information Sheets 1444 Fruit and Nut Review: Blackberries. Blackberry Jam 9 cups crushed blackberries 6 cups sugar Sterilize canning jars. Combine berries and sugar. Bring slowly to a boil, stirring occasionally until sugar dissolves. Cook rapidly to, or almost to, jellying point, (about 220 degrees F) depending upon whether a firm or soft jam is desired. As mixture thicken, stir frequently to prevent sticking. Pout hot jam into hot jars, leaving ¼” head space. Wipe jar rims and adjust lids. Process 5 minutes in a boiling water bath. Note: If seedless jam is preferred, crushed berries may be heated until soft and pressed through a sieve or food mill. Then, add sugar and proceed as above.
