How Long Do Raspberries Bloom?

The Raspberry Plant

• Raspberries must be planted in the spring, but they won’t begin to fruit until the following season. The plant’s canes live for two years; the first year produces a primocane that matures over the winter. The year-old primocane develops into a floricane in the spring. The floricane, which produces the fruit, dies after the berries have developed. Primocanes develop each year so the cycle of fruit production continues indefinitely. Primocanes (first year vegetation) have green stems. Floricanes are covered by a dark-brown bark.

Raspberry Cultivars

• Raspberries are classified by color and the plant’s fruit production habit. Fruits may be red, black, purple or yellow. Summer-bearing varieties, such as Bristol, Sentry and Liberty, produce one crop early in the summer. In warmer climates, the flowers bloom in early spring and produce fruit by late June. In cooler regions, the flowers bloom about one to two weeks later. Depending on weather, the harvest season typically lasts four to six weeks. Ever-bearing cultivars — usually red or yellow types such as Heritage, Red Wing and Fall Gold — produce one crop in the spring and one in the fall. They produce fruits in the late summer and autumn.

Planting Raspberries

• Plant disease-free raspberry cultivars in the early spring; the soil must be well-draining. Space requirements depend on the variety; red or yellow raspberries should be about 2 or 3 feet apart from each other with 6 feet between the rows. Purple and black raspberry plants should be 4 feet from each other with 8 feet between the rows. Roots grow horizontally and spread with their highest points 1 to 2 inches below the soil. Water the plants regularly. The plants need at least six hours of sunlight each day.

Pruning

• Prune summer raspberry plants twice a year — first in the spring and then after the berries are removed. In late March or early April, remove the weak and overly tall canes from the plant; they should be no higher than 5 feet. Do not damage newly developing primocanes. After the harvest in the fall, remove the used fruit-producing canes. Ever-bearing raspberry plants may be pruned once or twice a year.

Raspberry Plant Care

• Weed control and fertilization are necessary to keep raspberry plants healthy. Remove weeds by hand or herbicide and fertilize the plants with a mixture — ammonium nitrate, for example — that best suits the soil. Your local extension service or garden store professional can help you choose the right chemicals. Building a trellis over the raspberry plants will help them grow stronger and keep the wind from damaging the fruits. The trellis can be simple, such as stakes in the ground with twine strung between them. A sturdier construction of posts and wire strung about 12 feet apart will support larger berry gardens and last indefinitely, as the plants do.