This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
The Raspberry (Rubus Idceus), after the Gooseberry, Currant, and Strawberry, constitutes one of the most important market-garden crops. It differs in growth considerably from all other tree and bush fruits in that it bears its fruit on stems or "canes" of one season's growth, which naturally die away in the winter, never to live again. As a rule the young canes when developing bear five leaflets, but the next year, when fruiting, only bear three leaflets.
According to the returns of the Board of Agriculture there are about 9000 ac. of Raspberries grown in Great Britain, by far the larger portion being in England (6679 ac), Scotland having 2326 ac, of which over 1700 ac are in Perthshire. The industry here has been dealt with in the article on " Fruit Growing in Scotland" at p. 33. In England the largest Raspberry-growing counties are Kent, 2291 ac; Norfolk, 909 ac; Cambridge, 648 ac; and Middlesex, 328 ac Yorkshire, Cornwall, Essex. Worcester, Devon, and Lincolnshire come next, varying from 222 ac. in the first-named to 149 ac in the last.
Ireland is practically without Raspberries at present, only about 420 ac. being given for the whole country, while Wales has only 45 ac. of Raspberries to its credit. [J. W.]
Raspberries are surface-rooting plants that like light land, though they will not do better on thin soil that cannot hold some moisture than they will on land that is stiff and clayey. The method of planting is to place two yearling canes in a cut made by a spade, 18 in. apart in the rows and 5 ft. apart from row to row. The young canes should be cut down to 9 in. before growing time begins. During the summer they will throw up "spawn", i.e. young shoots, which become the fruiting wood for next year. For the first year these will be weak and bear little, but if the soil and cultivations are suitable they will become stronger and more numerous each year, until by the third year they are able to carry a crop of appreciable quantity. Raspberries like a good quantity of potash (see "Manures", Vol. I., p. 158), and pay for a topdressing of stable manure every fourth year. Do not dig among the roots more than is absolutely necessary.
The method of pruning is to cut out the last year's wood, thin out the young canes where too numerous to five or six, and then top according to strength of growth. Where the growth is vigorous, some system of tying the canes must be adopted, or else they will bend down with the weight of fruit, and it will draggle in the dirt. At Blairgowrie a system of strained wires is adopted, which has a very neat and workmanlike appearance, and, though of considerable initial cost, must last a long time, when once done, without further expense. Sometimes the canes are tied together in a bunch, on the principle that union is uprightness. Sometimes the canes are divided, and half from one stool is tied to half of the next stool, on the stand-together-or-fall-together principle. The system of growing Raspberries at Blairgowrie, in Perthshire, is described at p. 35.
The last two methods have the common disadvantage of bunching the canes together at the top, so that some must have difficulty in developing their fruit spurs. The Scotch plan has the advantage that the canes are tied singly along a wire, each being free to develop, and all being made secure against the brushing and swaying action caused by winds.
The gentleman's gardener plan of a stake and tie to each stool of canes is discarded on the ground of expense. Some growers cut the canes low enough to render them self-supporting. This can only be done without serious loss of fruit with certain varieties that grow a short stiff cane, such as Carter's Prolific or Steel's Victoria, and, to a less extent, Superlative.
The cost of canes is about £1 per 1000. The planting will cost about 1s. per 1000. The cost of cultivation will be the same as stated above for Currant and Gooseberries. The cost of manure on fairly good ground will be £4 per acre per annum. Pruning costs about 20s. to 25s. per acre. To this must be added the cost of tying if this should be necessary.