Black and Purple Raspberries
Black and Purple Raspberries
Black and purple raspberries are propagated by tip layers. When the cane tip of a black or purple raspberry touches the ground it roots and forms a new plant. Nurserymen use this characteristic to produce plants to sell. The plant is shipped with about 6 inches of old cane left on. This section of old cane is referred to as the handle.
Planting
The hole should be large enough to hold the root system without crowding. Set the plants and cover each with about 2 inches of soil. Cut off the handle right at the soil line to remove a possible source of anthracnose. These raspberries should be planted early to reduce potential injury to the growing points. If the plants are stored or heeled in too long they produce many thin spindly canes rather than a few, good, strong canes. If the plants have started to grow or or were otherwise stressed leave the handle on. This increases plant survival but also increases the risk of anthracnose. Any growth coming from the handle that produces berries should be removed. The handles of healthy plants may be removed before the plants are taken to the field for planting.
Training
Black and purple raspberries are grown in the linear system. Set plants 2 to 4 feet apart in rows 7 to 10 feet apart. The plants are easier to grow if some sort of trellis is provided for support. Properly pinched and pruned plants don't get too tall so a trellis may not be necessary. If the plants get too tall, some sort of trellis will be necessary to keep the plants from being blown over.
Pruning
When the new canes get slightly taller then 2 feet they are pinched to 2 feet. Purple raspberries are pinched at 2 1/2 feet. If the canes are pinched at these heights, a trellis may not be necessary. The pinching promotes the development of the side branches. It is on the branches where the best crops of berries are produced. The top 3 to 4 inches of canes are removed. If only the very tip of the cane is removed, the lateral may form a new upward growing tip. Pinching is more difficult in older fields because the fruiting canes are still present. Late pinching results in less productive side branches. The other aspect of summer pruning is the removal of the canes that have fruited. The canes are cut off as as close to the ground or crown as possible.
The dormant pruning deals mainly with the side branches. Only the first few buds on the side branches produce good berries so the side branches are shortened. The laterals of black raspberries are shortened to 6 or 8 inches. The laterals of purple raspberries are shortened to 8 to 10 inches. Canes that did not form side branches are cut off at 2 1/2 or 3 feet. When doing the dormant pruning take out any cane thinner than 1/2 inch.
Varieties
Black Raspberries Purple Raspberries Logan (New Logan) Sodus Cumberland Clyde Allen Bristol Huron--Less susceptible to Anthracnose
