Step-by-step Guide to Growing Raspberries
Rubus idaeus (fam. Rosaceae)
Hardy perennial prickly cane with a useful life of 12 years
Size: up to 2.5 m (8’) high unpruned; kept to about 1.2-1.5 m (4-5’) when fruiting
Yield: 1.5-3 kg (3-7 lb) per stool or 11-22 kg (25-49 lb) per 3 m (10’) row
Planting to harvesting time: 2 years
Of all soft fruit, raspberries are most suited to home growing. As they do not travel or keep well, raspberries freshly picked from your garden are likely to be far superior in quality and taste to store-bought ones. This is because most commercial varieties are not particularly flavourful, but have been bred to produce fruit which have the ability to withstand the rigours of packing and transport. The old variety Lloyd George, which is universally considered to be the best tasting raspberry, is rarely available in the shops because the berries quickly lose their shape once picked. By growing your own, you can choose from a wide range of flavourful varieties, and by planting for successional cropping, you can enjoy fresh raspberries from early summer through to the first autumn frosts.
Raspberries give very quick returns, and are second only to strawberries in. the length of time from planting until cropping. Although they will produce some fruit the first season they are planted, it is best not to allow them to do so. By pinching out the flowers as they appear, you are encouraging the young plants to develop strong stools and root systems instead of fruiting, and the canes should then produce heavy crops from the second season onwards. Unlike strawberries, which are disease-prone and need replanting every three years or so, well cultivated raspberry canes will continue to be fruitful for at least twelve years.
The plant itself, Rubus idaeus, is a native of Europe, including Britain, and parts of Asia. It can often be found growing wild in hedgerows and on hilly heathland with acid soils. Many of these plants are garden escapes, the seeds having been scattered by birds. Although most raspberries have red or purplish-red berries, there are richly-flavoured yellow-fruited varieties (sometimes known as white raspberries) and also black raspberries. These black-fruited types, derived from R. occidentals, are much more popular in America than Europe, and are widely cultivated there. Unlike the raspberry, which has a spreading habit of growth, black raspberries are clump-forming, with heavier and more branched canes.
Raspberries flower and fruit on laterals growing from canes which were produced the previous year, after which the fruiting canes die, and are replaced by new canes. Although most varieties fruit in mid-summer, there are some types which are specifically cultivated for autumn crops. These autumn fruiting, or everbearing, raspberries produce fruit on the tips of the current season’s shoots. Fruit quantity may be smaller than that of summer fruiting canes. Summer and autumn fruiting varieties require slightly different methods of pruning, but neither method is particularly difficult or time consuming. The variety Lloyd George can be pruned to crop early, mid-season or in autumn, and traditionally some bushes in the fruit cage were pruned for early cropping and the rest pruned for maincrop and late picking.
Suitable site and
Raspberries do best in a sunny site, but being woodland plants, they will tolerate some shade. Because they flower relatively late in the season, frost is not usually damaging and low-lying sites can be satisfactory for growing raspberries in most years, unless there is a very late frost. They will not tolerate waterlogged soil, however, and in very wet winters, excessive water will kill the roots.
Besides soil drainage,from wind is the second major consideration. The canes are fairly brittle and may snap off in high winds, and the point where the fruiting laterals join the canes is also very vulnerable to serious damage from strong winds.
The best soils are deep, rich, well-drained loams, as long as they retain some moisture in dry weather. Shallow sands and gravels can be made suitable, if you are prepared to water them frequently and give a continual supply of nutrients. Likewise, heavy clay soils are not really suitable without careful preparation and maintenance, because they tend to harden and crack in dry summers depriving the shallow roots of water. Raspberries will accept more acid conditions than most other soft fruits, but readily become chlorotic in too alkaline a soil. Shallow soils over chalk should be avoided.
Because some viral infections are soil-borne by eelworms, avoid planting new canes in sites previously occupied by berries of the same genus and plant as far away as possible from old fruiting canes.
Begin soil preparation well in advance. Remember that the plants will remain in the ground for at least 12 years and no amount of aftercare will make up for inadequate preparation. Whatever the soil type, make sure the ground is completely free from perennial, such as couch, bindweed and nettles. If the subsoil is hard and impervious to water, break it up with a fork. Then fork in well-rotted manure at the rate of 12 L per plant. At the same time, apply superphosphate, at the rate of 30 g per sq m (1 oz per sq yd). If manure is not available, use garden , leaf-mould or moist peat.