Raspberries grow best in a well-drained but moisture retentive, fertile soil in a sunny position. Ideally, the soil should be slightly acid with a pH of 6-6.5. This can easily be checked by using a soil test kit or pH meter. Deep soil cultivation is recommended, preferably digging to the depth of a spade, plus forking of the soil layer below. Incorporate a good dressing of well rotted manure or garden compost. Be sure to remove all traces of perennial weeds. If growing in a Container, choose a large container such as a half barrel.
We would recommend using a John Innes number 3 potting compost. Depending on the container size, plant 3–6 canes and provide a support, either canes or trellis. Keep the plants well watered and when in growth feed regularly with a high potash liquid fertilizer. Prune as described for the type being grown.Your raspberry plants will need reporting and thinning out after about 3 years.
Raspberry Growing: Summer Fruiting – (Floricane) Types
Summer cropping varieties grow to a height of 1.8 metres (6′) or more and they require some form of support, though it is not essential to arrange this before planting. The long stems (known as canes) that are produced can be tied to wires (12-14 gauge) against a wall, fence or garden shed. It is better to plant Raspberries in the open garden and to tie the canes to wires strained on stout posts.
This way, good light and air circulation are achieved. When raspberry growing if possible, run the rows north to south as this will permit maximum light penetration into the crop. Should there be more then one row, leave 1.8 metres (6′) between them. Bear in mind, when siting the plants that birds are attracted to the ripening fruits and protection is advisable. If a fruit cage is available, plant the Raspberries in this or position them so that a cage or netting can be easily erected over the plants if required.
To support the plants, erect stout posts, 2.4 metres (8′) long with about 60cm (2′) buried below soil level. Stretch wire, horizontally, between the posts with the strands at 60cm (2′), 1.2 metres (4′) and 1.65 metres (5½’) above ground level. The end posts should be supported with struts at 45° so that they can better withstand the wire tension.
Planting and Initial Treatment
Raspberries may be planted at any time during the dormant period provided that soil and weather conditions are favourable. Plant your raspberries as soon as possible after receipt but not when the soil is very wet or frozen. After digging, it is best to allow the ground to settle for a week or two before planting is undertaken. Remove the polythene and protective material from around the roots. Soak them in tepid water for a few hours if at all dry.
The raspberry canes should be planted 45cm (18″) apart and a garden line should be used to ensure that the row is straight. Dig a planting hole large enough to accommodate the root system without squashing and set the plants so that the roots are covered by about 8cm (3″) of soil. Gradually fill the soil around the roots and firm well. Take care not to damage any young, new shoots which are developing among the roots. If hard frosts occur, newly planted material may need re-firming after the thaw, gently tease out the roots of pot grown plants and plant so that they are 2.5–4cm (1–2″) deeper than the compost level.
Should planting not be possible for some time, ‘heel’ in the bare root plants temporarily. To do this, dig a shallow V-shaped trench, set the plants close together along one side of this trench, replace the soil and firm it around the roots. Before or immediately after planting, prune the existing canes to 22cm (9″) from the ground. When new shoots have developed from the base of the plants and they are about 20cm (8″) tall, cut down what remains of the old canes to ground level.
Training and Pruning
When raspberry growing, the fruit will not be produced in the first season but the new canes that develop should be tied to the wires. These canes will carry the crop in the following year. At the end of the first summer, cut out, down to soil level, any weak canes – but retain the strong ones. In the following February, it is traditional to prune the tips of these canes, cutting them back to a growth bud about 15cm (6″) above the top wire.
Research has shown that cane length shortening by more than 15 cm (6″) reduces the crop yield and, to avoid this, the tips of long canes should be bowed over and tied down to the top wire. In the year following planting (the second season), further new canes develop from ground level. Initially, while the old canes are fruiting, the new ones may need a loop or two of twine to keep them upright. Once harvesting has been completed, remove the old canes entirely, pruning down to soil level.
Cut out weak, new growth and any surplus, strong canes so as to leave about 6 of the strongest per plant. Tie them to the wires and space them 8-10cm (3-4″) apart along the top wire. Canes that develop well away from the plants and between rows should be pulled up while they are small to minimise competition. The sequence of old cane removal and the tying in of new canes is repeated each year.
Feeding and Cultivation
In March apply Sulphate of Potash at 35g per sq. metre (1oz per sq. yard) and Sulphate of Ammonia at 15g per sq. metre (½oz per sq. yard). Poor growth and pale green foliage are a likely indication of nitrogen shortage, in which case a further application of Sulphate of Ammonia can be given in the late spring. Every 2 or 3 years, use a general fertiliser, such as Growmore, in March instead of separate fertilisers. In late April when the soil is moist, apply a surface layer (mulch) of well rotted manure or garden compost.
Ensure that your raspberry plants do not become short of water especially as establishment is taking place following planting, and also during June and July when fruits and new canes are developing. Apply a minimum of 10-15 litres per sq. metre (2-3 gallons per sq. yard) on each occasion of watering. Control annual weeds by light hoeing but do not hoe or cultivate close to the plants as they have shallow roots which can be damaged. (Note that the new canes of some early summer fruiting varieties may produce a few fruits at the end of the first season, these can be picked and will not affect the following year’s crop)
Raspberry Growing: Autumn Fruiting (prim ocane) Raspberry Types
Such raspberry varieties produce fruit on the current year’s growth which matures more rapidly than summer fruiting types thus; a crop will be carried in the first season.
Follow the general directions as given for summer varieties. Plant 60cm (2′) apart in the rows with 2.2 metres (7′) between rows. These distances are greater than for summer fruiting varieties to allow room for the development of more canes per plant. Each raspberry cane will bear less fruit than will summer cropping varieties so it is good policy to leave more of them and, thus, increase the yield per plant. Fruits will ripen from late summer through to the first frosts and will appear little and often.
Immediately after planting, cut the canes down to 22cm (9″). When new shoots have developed from the base of the plants, cut the old canes away at ground level. In subsequent years, cut out all canes to ground level during the winter – not later than February**. With established plants, many new shoots will grow in the spring. Leave them to develop over a strip of ground so that each row bed is 75-90cm (2½-3′) wide. Hoe out those appearing outside the strip. If necessary thin out the shoots to leave them 8-10cm (3-4″) apart. **Recent research has shown that if a few canes are left on autumn fruiting raspberries a small extra early crop of summer fruit will be borne. This does not appear to significantly reduce the capacity of the canes to fruit again in the autumn. To take advantage of this leave some autumn canes uncut and wait for fruit in June then remove immediately leaving new canes to mature as above.
Other Cultural Treatment
Autumn fruiting varieties do not grow as tall as the summer types and permanent supports are not necessary. To prevent the canes on the outside of the bed(s) from bending to the ground during the fruiting period, temporary support may be given by running string, tied to 1.2 metres (4′) stakes, around the row(s). Feeding can be undertaken as for summer fruiting varieties and the plants should not be allowed to become short of water, especially as the fruits are developing. As with summer varieties, birds can be attracted to the fruits so that the protection of a fruit cage or netting may be required.
Long Cane Raspberries
These special canes are delivered with most of the mature wood from the previous season still intact, the
advantage being that it will fruit on this wood in the year of planting. The technique was developed to allow commercial plantations to yield fruit more quickly and so yield revenue. It allows gardeners to pick fruit in a matter of weeks! As a large amount of leaf will quickly develop on canes that have very little new root it is crucial that great care is taken to provide sufficient water particularly in the first year. Once fruiting has finished the raspberry canes should be treated as summer fruiting types.
All Raspberries in addition to being eaten fresh, are excellent for freezing to use at a later date. Use one of the varieties recommended for freezing. Choose fruits that are fully ripe and do not wash them unless necessary. Once picked, keep the fruit cool and freeze as soon as possible. Spread out the fruit in a single layer on a metal tray and freeze. Once the fruits are firm put into plastic bags or plastic containers and seal and store in the freezer.
Alternatively, turn the fruits gently in dry sugar until they are evenly coated. Use about 60g caster sugar per 500g of fruit (2oz sugar to 1lb fruit), but more may be used according to taste, or can be added on thawing. Sprinkle a tablespoonful of cold water on the fruits before adding the sugar. After the fruits have been coated, leave them in a covered bowl for 2 hours to allow the sugar to draw sufficient moisture from the fruit to provide a coating of syrup. Pack the coated fruits in containers and place in the freezer.
Two plants can be grown in an area of 1 sq metre. Prepare the ground and plant the pot raised plants as previously described. Plant a single plant between two stakes spaced 1m (3ft) apart. New growth is tied to one of the stakes; these will produce a crop from August to October.
Trim back the canes in February, removing the top 15cm (6”) of growth. New canes produced the following year are tied to the other stake which will produce the late summer/autumn crop. Once the old canes have fruited in June these are cut back to the ground.