How to grow strawberries

Summer-fruiting, perpetual or alpine

Summer-fruiting strawberries give the largest fruit, says the RHS. They crop for two or three weeks, somewhere between early June and early August, depending on whether the variety is early, mid or late season. BBC Gardeners' World suggests growing a mix of early, mid and late varieties to stretch the harvest.

Perpetual strawberries, also called everbearers, give small flushes of smaller fruit from early summer to early autumn, sometimes until the first frosts. They make fewer runners. BBC Gardeners' World recommends them for small gardens.

Alpine strawberries (*Fragaria vesca*) give small crops of tiny, aromatic berries over summer. Most are red, though some are white or yellow. BBC Gardeners' World says they suit semi shade and pots.

When to plant

The RHS plants in spring, late summer or early autumn. Planting in August or September lets plants settle in before they fruit the following year. BBC Gardeners' World plants bare-root runners in late summer to early autumn and pot-grown plants in late summer, early autumn or spring, by May at the latest. It avoids winter and early spring, because strawberries dislike being planted into cold, wet soil.

Cold-stored runners are a shortcut. They are sold in spring and early summer, should be planted straight away, and can fruit about 60 days after planting, according to the RHS. BBC Gardeners' World says some nurseries supply them from April to June and they crop in their first summer.

Garden Organic gives two planting windows: September to October and late March to May.

Site, soil and the crown

Choose a sheltered, sunny spot. The RHS says plants tolerate some shade but fruit best in full sun, and to avoid frost pockets, because late frosts damage the flowers. Strawberries like fertile, well-drained, slightly acidic soil. On poor or heavy soil, the RHS suggests raised beds.

Before planting, weed the bed and dig in two bucketfuls of well-rotted organic matter per square metre, ideally a few weeks ahead.

Spacing. The RHS plants 35–40 cm apart in rows about 75 cm apart. BBC Gardeners' World uses 30–45 cm in rows 75 cm apart, and Garden Organic 30–40 cm in rows 60 cm apart.

The crown matters most. The RHS warns that if the crown is planted too deeply it will rot, and if too shallowly the plant dries out quickly. The crown should rest lightly on the surface. Trim long roots to 10 cm if needed.

Strawberries in pots and under cover

In a large container, the RHS spaces plants about 20 cm apart in peat-free multi-purpose or soil-based compost, with the crown level with the surface. Pots keep plants away from soil diseases and reduce slug damage, but vine weevil can be a problem. The RHS advises against traditional strawberry pots with planting holes in the sides, because they make plants harder to keep healthy. BBC Gardeners' World fits six to eight plants in a growing bag.

For an earlier crop, the RHS grows strawberries under cloches or in an unheated greenhouse or cold frame. Cloches give fruit at least a week early, and an unheated greenhouse about two weeks early. Move pots under cover in February, and pollinate the flowers by hand with a soft paintbrush.

Watering, feeding and straw

Water new plants regularly while they establish, and all plants during long dry spells, says the RHS. Pots and hanging baskets dry out quickly. Keep water off the crown and fruit and water in the morning.

Feeding. Plants in good, regularly mulched soil are unlikely to need extra feed, says the RHS. If harvests are poor, give an organic high potassium granular fertiliser in spring. Feed plants in pots and growing bags every fortnight during the growing season: a general purpose liquid feed at first, then a high potassium feed once the first flower buds form. BBC Gardeners' World feeds a high potash feed every week or two from early spring.

Straw. When fruit starts to form, tuck dry straw under the plants to keep the berries clean. The RHS says wheat straw is fine and barley straw is softer. BBC Gardeners' World adds that straw deters slugs and snails and suppresses weeds. The RHS removes it in autumn.

Frost and birds

Strawberry plants are hardy, but the flowers are not. When frost is forecast during flowering or early fruiting, the RHS covers plants overnight with fleece, hessian or an old bedsheet. The RHS calls strawberry black eye the most recognisable form of frost damage, and flowers affected by it will not set fruit. BBC Gardeners' World notes that a late frost in May can damage growth.

Birds are the other threat. BBC Gardeners' World names blackbirds as especially fond of the fruit. The RHS builds a frame of canes or wood and stretches netting tightly over it before the berries ripen. Loose netting can trap birds, hedgehogs and slow worms, so BBC Gardeners' World prefers a fixed cage with holes big enough for pollinators. Garden Organic also says to make sure the netting is well secured.

After fruiting: runners, tidying and new plants

Cut back. After cropping, the RHS cuts the old leaves of summer-fruiting plants about 10 cm above the crown. BBC Gardeners' World cuts to about 5 cm above ground level and feeds with a general purpose fertiliser. On perpetuals, the RHS removes only dead, damaged or diseased leaves.

Runners. Late summer is the ideal time to root runners, the plantlets on long stems. The RHS sets 9 cm pots of peat-free compost beside the plant, pegs the runner in with a U-shaped wire, keeps the compost moist and cuts the young plant free once it has rooted. Remove any runners you do not need.

Replace the bed. A bed usually crops well for up to four years, says the RHS, and should be replanted every three or four years in a different spot to avoid disease building up. Garden Organic replaces plants every three years.

Common problems

Grey mould (*Botrytis cinerea*) causes soft decay and fuzzy growth on the fruit. Keep water off the crown and fruit, says the RHS. BBC Gardeners' World adds watering in the morning, keeping the soil clear of debris and removing damaged fruit.

Powdery mildew gives white, powdery leaves in hot, dry summers, says BBC Gardeners' World. Keep the soil moist, remove affected leaves and space plants widely.

Vine weevil larvae eat the roots and are a bigger threat in pots. BBC Gardeners' World uses a biological control in late summer and autumn. Slugs and snails like damp straw and mulch. The RHS also lists spotted wing drosophila, a fruit fly that damages the berries. If you use any plant protection product, use only one authorised in the UK and follow the label.