When to plant strawberries?

When, by region

Spring, late summer and early autumn, and August or September planting so plants root before the next crop, are from the RHS. The same guide gives the 35–40 cm spacing, rows about 75 cm apart, the crown level with the soil, and about 20 cm in a pot. Cold-stored runners are sold from spring to early summer, planted as soon as they arrive, and in good conditions they fruit about 60 days later. The season running from September to April, and the advice to skip midwinter on wet, cold ground, is from the RHS bare-root guide. The wider calendar is the planting calendar.

Crown, spacing, pots

Dig a hole large enough for the roots, water it, and if the roots are long the RHS trims them to 10 cm (4 in) and spreads them in the hole. The base of the crown rests on the surface: buried, it rots; left too high, the plant dries out. Firm with your fingers and water.

In the ground, 35–40 cm (14–16 in) along the row and about 75 cm (30 in) between rows. In a wide pot, about 20 cm (8 in) between plants, crown level with the compost, in sun and out of the wind. Pots with holes up the sides are awkward to keep healthy: the RHS says so. A wide container and a peat-free multi-purpose compost are enough. Pot size and watering on a balcony are in the container garden.

Before planting, clear the weeds and dig in two bucketfuls of well-rotted compost or manure per square metre, a few weeks ahead, so the soil can settle. On poor soil the RHS prefers a raised bed, which drains better and gives the roots more depth. Choose a sunny, sheltered spot. Some shade is tolerated, but the sweetest fruit comes in the sun.

Water, straw, frost on the flowers

Water new plants while they establish, and all strawberries in dry spells. In a pot, and more so in a hanging basket, the compost dries out fast. Water in the morning, and keep it off the crown and the fruit: damp there encourages grey mould. How much, in a dry summer, is in the watering guide.

Once fruits start to form, a layer of straw keeps them off wet soil. It does not go over the crown: damp material against it rots the plant. Take the straw off in autumn, because once wet it shelters slugs and fungi. Well-rotted compost in late winter or early spring is another cover: depth and materials are in mulching, still with a gap around the crown.

The plant takes cold. The flowers do not. If frost is forecast while they are in flower or carrying early fruit, the RHS covers them overnight with fleece or a sheet, and uncovers them by day. A site prone to late frosts damages the flowers: that is black eye, the centre of the flower blackening so no fruit follows. On summer-fruiting plants set out in autumn or spring, remove the first flowers only if the plant is weak and growing slowly. On perpetual plants set out in spring, removing the first flush helps them establish. On cold-stored runners, leave the flowers.

How many years, and the runners

A healthy bed, on fertile soil that drains, crops well for up to four years, the RHS says. Then replant, every three or four years, somewhere else, so soil diseases do not build up. A pot sidesteps that, but vine weevil hits containers more often: checks sit under pests and diseases.

Runners you do not need come off, or the bed thickens. To make new plants, in late summer, set a 9 cm (3½ in) pot of compost beside the plant, peg the runner with a U of wire about 15 cm (6 in) long, and keep the compost just moist. Sever it from the parent once it has roots. Perpetual varieties make few runners: you often have to buy them.

An unheated greenhouse or cloches bring the crop forward. The RHS gives about a week under cloches and about two weeks in an unheated greenhouse, by moving pots under cover in February or covering the rows. Open the covers by day while the plants are in flower, so insects can pollinate, or pass a soft brush over the flowers.