There are two types of blackberries, the erect and the trailing. The trailing blackberry is also called dewberry. These are usually tied to trellises and ripen earlier than the erect types.
A good moisture supply is needed, especially when the fruit are ripening. If the site is low or poorly drained, winter hardiness of the plants is reduced. Do not be plant in low areas likely to be frost pockets.
The erect types are propagated by suckers or root cuttings with root cuttings preferred. Trailing types may be propagated from root cuttings or tip layers. Thornless varieties only come true from tip layers.
Plants that can't be planted immediately can be heeled in. If the plants are dry, soak them in water for several hours prior to planting. Before or just after planting cut the tops back to 6 inches. The planting depth should be the same as it was in the nursery. Plant erect types 5 feet apart in rows which are 8 feet apart with trailing varieties 4 to 6 feet apart in rows 8 feet apart. Vigorous trailing varieties are spaced at 8 to 12 foot spacings in rows 10 feet apart.
Erect blackberries are most easily trained to a single wire suspended 30 inches from the ground. As canes grow they are tied to the wire when they cross it.
The trailing types are trained to a 2 wire trellis. The first wire is 3 feet from the ground and the second wire is 5 feet from the ground. The canes are tied horizontally along the wire or the canes are fanned out then tied to a wire where they cross. Sometimes the canes fruiting this year are tied on one wire and canes fruiting the following year are tied on the other wire.
The cane tips of erect blackberries are pinched out in summer when the canes are 30 to 36 inches tall. The pinching stimulates the formation of laterals. In winter, cut the laterals back to 12 inches. Remove fruiting canes once the crop has been harvested. When the fruiting canes are being removed, thin out the new canes. Leave 3 to 4 new canes on each plant or 5 to 6 canes per linear foot or row. Remove all suckers that appear between the rows.
Pruning trailing types is not as complicated. When the fruit have been harvested, remove the canes which produced the crop. At the same time thin the new canes. Leave 8 to 12 canes or if the variety is a semi-trailing leave 4 to 8 canes.
Blackberries are fertilized when they blossom. Use 5- 10-5 fertilizer at 5 to 10 pounds per 50 feet of row.
Cultivation is the primary means of weed control. Cultivate only 2 to 3 inches deep near the row. Stop cultivating about a month before freezing weather arrives.
Trailing varieties may not be as hardy as the erect types in Michigan.
Erect Blackberry Varieties Trailing Blackberry Varieties Alfred Lucretia (may need winter Baily protection) Darrow Hedrick