RASPBERRY

The wild raspberry (Rubus idaeus) is said to owe its specific name to the abundance of wild raspberries on Mount Ida in Crete in classical times. The first mention of this fruit in Britain is in the writings of William Turner, a sixteenth century herbalist, who commented ‘The taste of it is soure’. (Black and red currants and tomatoes are other fruits which were at one time despised in this country.) Until the nineteenth century raspberries were seldom regarded as good eating, being considered more suitable for flavouring medicines and drinks.

Soil Preparation and Planting:

Raspberries require a soil with good moisture-holding capacity. Badly-drained land which tends to become waterlogged is quite useless. They tolerate partial shade. Farmyard manure, leaf mould, compost, peat and similar materials should be well mixed with the soil before planting. Plant each cane firmly, the roots being covered by 2—3 in. of soil and set 2 ft. apart, allowing 5 ft. between rows extra vigorous varieties like Mailing Promise, Mailing Exploit and Norfolk Giant may be allowed 3 ft. with 6 ft. between rows. In Scotland commercial growers sometimes plant two canes together, the planting distance being about 2 ft. 6 in. They claim that this method (which is also practised in the north of England) produces a heavier total yield than planting singly.

If possible, rows should run north and south. After planting, cut the canes down to 12 in. from soil level. The remaining buds will produce a few fruits in the summer. This treatment encourages the production of really strong canes for the following year.

Supports are essential. Strong posts, approximately 6 ft. high, must be in position before planting. Two or three strands of wire at equal distances are joined to the posts.

Manuring of Raspberries:

Lawn mowings, compost, peat or farmyard manure may be applied as a mulch in late spring, raspberries being very liable to suffer from summer drought. Mailing Promise will, however stand up quite well to prolonged drought. Annual dressings of sulphate of potash in late winter or early spring (muriate of potash is harmful to raspberries) at the rate of 2 oz. per sq. yd., are recommended. A complete fertiliser may also be applied in February. Raspberries produce a large number of surface roots and care must be taken to avoid damaging these when weeding. Avoid any cultural operations of a deep nature.

Pruning and Propagation:

Pruning is much the same as for the old-fashioned wichuraiana rambler roses like Excelsa and Sanders’ White, all fruiting canes being removed after picking. Tie in the new canes at the same time, allowing 4 to 6 strong canes to each plant, and removing the weakest. In February tip the canes to a uniform height to get rid or any unripened wood.

Growths springing up between the rows (usually known as spawn or suckers) should be cut out as they appear. If additional plants are wanted, remove the strongest in early autumn and plant in their permanent quarters. Never take suckers from unhealthy plants.

How to Pick Raspberries:

Always pick raspberries when absolutely dry, otherwise they will rapidly turn mouldy. If wanted for immediate use, jam or preserving, leave the core on die stalk so that the raspberries are ‘plugged’. For exhibition the fruits must be shown on the stalks, as with strawberries, gooseberries and other soft fruits. If it is not intended to use the fruits for another 24 hours, they may be picked just before they are really ripe. Raspberries never keep for more than a day or two, and must be eaten at once, unless the fruits are required for jam making when a pulpy mass is perhaps less important! Picking at least every other day appears to give higher yields than picking, say, every four or five days.

Choice of Varieties:

If clean virus-free plants of Hoyd George such as the Amos and New Zealand Hoyd George strains are secured, there is no better raspberry. Mailing Exploit and Mailing Promise are excellent alternatives. There are several other Mailing varieties, e.g. M. Jewel and M. Notable, the latter doing well in the north despite a tendency for the canes to bend over.

Hailsham: an autumn-fruiting variety which should receive similar treatment to Hoyd George.

Hoyd George: a heavy cropping, very sweet raspberry, fruiting in summer and autumn. Fruits travel satisfactorily. Although usually grown as a summer-fruiting variety, good results are obtained by ‘treating as an autumn variety and removing all fruiting canes in February or March.

The new canes will then bear fruit the same autumn. Very subject to the virus disease known as mosaic, and plants raised from virus-free stocks should be obtained.

Mailing Exploit: some consider this the finest raspberry extant. It is usually ready 10—14 days after Mailing Promise. A very heavy cropper with rather larger fruits of excellent flavour, borne at the tips of the trusses. The fruits are hidden to some extent by the leaves. Lateral shoots inclined to break in windy weather, and in exposed positions Mailing Promise may be a better choice.

Mailing Promise: an outstanding modern variety which is a heavy cropper, making an abundance of new canes when young. Slightly liable to frost damage. Does well in Scotland. Succeeds on poor soils. The berries are liable to rot in wet seasons and are sometimes hard at the tips. Makes excellent jam. Ready about mid-June.

Norfolk Giant: the last summer raspberry to ripen, usually escaping frost damage. A strong grower, even on light soils. Crops heavily. Excellent variety for jam making, as the berries do not ‘run’ in wet weather. Also popular for bottling, canning and quick-freezing, despite the rather indifferent flavour.

Pyne’s Imperial: does well on light, dry soils. Strong grower and heavy cropper. Berries large and firm, of good flavour. Should not be gathered until the berries are ‘dead’ ripe. Makes first-class jam. It is a pity that the berries are not sweeter, as this is apparently the only fault.

Red Cross: an early variety which fares well on poor soils. Heavy cropper.

Berries stand out from the leaves and may need more than the usual protection from birds. Resistant to drought. Valuable for bottling, cooking and jam-making.

Yellow Antwerp: a yellow variety of excellent flavour. Does not always grow as strongly as other varieties. There are very few yellow kinds and another yellow, Golden Everest, is worth a place in gardens.

Insect Pests and Fungus Diseases.

Raspberry Aphids or Greenjly. Several species of aphids attack raspberries and overwintering eggs are laid on the canes. These can be killed by a 5% tar-oil spray if necessary. Summer spraying with derris and nicotine may also be carried out as required.

It is possible that the aphids also act as carriers of virus diseases. New Zealand produces excellent virus-free stocks, presumably due to the absence of raspberry aphids. This can be compared with seed potato production in Scotland, Northern Ireland etc. where the potato greenfly population is virtually nonexistent. (Aphids generally do not flourish in areas which are windy and possess a high rainfall.) Raspberry and Loganberry Beetle. Symptoms: Raspberries, loganberries and blackberries are all liable to attack. Adult beetles about one-sixth of an inch long emerge in May and feed on blossom buds and young foliage. Eggs are laid in the open blossoms during June and July, hatching in about 10 days. The young larvae are the maggots seen in the fruits. They feed on the outer surface of the fruitlets, and subsequently on the inner tissues, including the ‘plug’.

This pest is easily mastered by applying a derris insecticide but correct timing is of vital importance. To control the beetles apply the derris dust as soon as they are observed in large numbers. Repeat about 10 days later. For the third application, again about 10 days later, to kill any young grubs feeding on the outside of the fruit, a derris spray is advised — dusting leaves an unsightly deposit on the fruit.

Blue Stripe Wilt. Symptoms: The fungus enters through the roots in the spring. Infected canes are stunted in growth, with a consequent reduction in crop. With very severe attacks, leaves turn yellow and wilt, the canes eventually dying.

On young canes, symptoms do not appear until July, when diseased specimens show a distinct blue stripe, which starts towards the base, and may finally surround the stem.

Where attacks are not severe, infected canes may be removed, but with heavy infections the entire plant or ‘hill’ should be dug up and burned. Cane Midge. This pest is mainly troublesome in the south-east. It feeds under the rind of young shoots in May. Further attacks may occur in July and from late August well into September. Injury by cane midge opens the way for entry of fungi which may eventually cause the death of the cane.

An insecticide spray applied in May just before the flowers open gives good control.

Cane Spot Anthracnose. Symptoms: Raspberries, loganberries and blackberries are liable to infection. Young canes exhibit small, round reddish-purple spots from late May or early June onwards. These spots develop a white centre as they increase in size. Leaves, leaf-stalks and fruits may also be attacked. Growth is stunted (canes often die back) and there is a consequent reduction in crop. Norfolk Giant is a susceptible variety. Treatment: Apply a thiram fungicide when the buds are about y2 in. long and repeat when they turn white. Aim at a really thorough coverage of canes and foliage.

Raspberry Moth. Symptoms: This is a common pest throughout England and Scotland. Raspberry canes which winter in spring have usually been attacked by raspberry moth. The moth lays its eggs in the open flowers and the young grubs bore into the ‘plug’ of the fruit. When the berries start to colour, the grub departs to hibernate in the base of the canes, in cracks on supporting stakes, in garden rubbish generally or in the soil. It emerges the following April and bores into the base of the cane where it feeds on the pith. This may eventually result in the collapse of the cane. Treatment: Common sense hygiene, I.e. the removal of all rubbish to destroy over-wintering cocoons. An insecticide spray applied in early April controls raspberry moth but careful timing is imperative. An earlier, alternative treatment is to spray the soil with tar-oil winter wash in late February. An 8% solution is desirable.

Raspberry Mosaic. Symptoms: This disease is largely responsible for the decline in the raspberry acreage. Leaves are mottled with yellow spots and are sometimes curled. The vigour of the canes is greatly reduced. Infection spreads rapidly. Hoyd George is extremely susceptible. Treatment: Remove and burn infected plants. Plant only healthy canes from a sound strain.

Sorry, comments are closed for this post.