Raspberry

The Raspberry or Red Raspberry (Rubus idaeus) is a plant that produces a tart, sweet, red composite fruit in late summer or early autumn. In proper botanical language, it is not a berry at all, but instead an aggregate fruit of numerous drupelets around a central core. In raspberry and other species of the subgenus Idaeobatus, the drupelets separate from the core when picked, leaving a hollow fruit, whereas in blackberry the drupelets stay attached to the core.

It typically grows in forest clearings or fields, particularly where fire or wood-cutting has produced open space for colonization by this opportunistic colonizer of disturbed soil. The raspberry flower can be a major nectar source for honeybees. As a cultivated plant in moist temperate regions, it is easy to grow and has a tendency to spread unless cut back.

Two types are commercially available: the wild-type summer bearing, that produces an abundance of fruit on second-year canes within a relatively short period in midsummer, and double- or "ever"-bearing plants, which also bear a few fruit on first-year canes in the autumn, as well as the summer crop on second-year canes. In the United States, Raspberries can be cultivated from USDA plant hardiness zones 3 to 9.

Leaves of the raspberry cane are used fresh or dried in herbal and medicinal teas. The leaves have an astringent flavour and in herbal medicine are reputed to be effective in regulating menses.

Raspberries contain significant amounts of polyphenol antioxidants, chemicals linked to promoting endothelial and cardiovascular health. Xylitol, a sugar alcohol alternative sweetener, can be extracted from raspberries.

Growing

Raspberries are grown for two reasons: for the fresh market, and for commercial processing. Traditionally raspberries were a late summer crop, but with new technology, varieties and innovations, raspberries can be enjoyed all year-round. Raspberries need a lot of sun and ample amounts of water in order to develop to their fullest. Escaped raspberries frequently appear as garden weeds, spread by seeds found in the excrement of birds.

Culture

Raspberries are normally started in the winter from dormant canes. These should be planted 1m apart in fertile, well drained soil. Prepare the soil before planting by digging deeply and incorporate plenty of organic matter, such as compost.

In the first year, remove all flowers to allow the plant to build up reserves and to grow bigger. From the second year, previous year's canes will flower in the spring and the fruit will ripen in the summer. Water and feed well in the spring and summer, but decrease water and food in the autumn. This will harden the canes to survive the winter.

In the winter, prune out old flowered canes, down to the ground level. Of the new canes, remove all small and weak ones. Remove ones that are growing too close to each other - allow around 10-15cm between canes. Most varieties will need to be staked.

Raspberries are very vigorous and can be a little invasive. They will succer new canes some distance from the main plant. In the spring, mark out the boundary of the plant and push a spade straight down the boundary. This will sever the suckers. Then dig out the suckers that grow outside the boundary.

Pick the fruits when they have turned a deep red and drop off easily from the core when touched. This is when the fruits are most ripe and sweetest. Excess fruit can be made to raspberry jam or frozen.

Varieties

Recent breeding has resulted in varieties that are thornless and upright (does not require staking). Raspberries have also been crossed with other member of the Rubus genus, resulting in a number of hybrids, such as boysenberry and loganberry.

A gold raspberry, which is pale yellow, has been selected by horticulturalists.

The black raspberry, also called a blackcap, is not the same plant, being a cultivar (usually) of Rubus occidentalis, a North American species. Other Rubus species also called raspberries include:

Arctic raspberry (Rubus arcticus)
Flowering raspberry (Rubus odoratus)
Wine raspberry (Rubus phoenicolasius)
Whitebark raspberry or Western Raspberry (Rubus leucodermis)

Not all of these are included in the same subgenus.

Images

Image:Raspberry (red).jpg|raspberry (red) - watercolor 1892 Image:Raspberry (black).jpg|raspberry (black) - watercolor 1893 Image:Raspberries_Yellowjacket.jpg|Raspberries and a wasp Image:Raspberries05.jpg|Raspberries Image:Black_raspberry.jpg|Black Raspberries - (Rubus occidentalis)

Diseases and pests

Raspberries are sometimes eaten by the larvae of some Lepidoptera species - see list of Lepidoptera which feed on Rubus.

External links

Fruit | Rubus