How to Plant Strawberries: Crown Depth and Which Way to Face Them

Plant in autumn, while the soil is still warm

Strawberries want to be planted while there is still enough warmth in the soil for the roots to grow, which in most gardens means mid autumn. Plant late and the roots go into winter without having spread, and the flower trusses in spring are small.

Planting too early costs you as well. Set out in the heat of late summer, the plant makes leaf instead of settling towards dormancy, and flower bud formation is slower. Flower buds form as the days shorten and temperatures fall, so the aim is to have the roots settled just before that.

If you are planting late, do not disturb the rootball, and mulch generously around the crown with husks or leaf mold to hold some warmth in the soil.

How to pick a good plant

Pick plants up one at a time and look at them. What matters is not the price or the number of leaves but the thickness of the crown and the color of the roots. Get those two right and a plant with few leaves still catches up before winter.

1. A thick crown The crown is the short stem at the center of the plant. Look for one about as thick as a pencil, around half an inch (1 cm) across. Next spring's flower trusses are packed inside it, so thickness translates directly into fruit.
2. Three to five true leaves Too many leaves can mean a stretched or an ageing plant. You want dark, thick leaves on short, firm stalks. Avoid anything with a lot of yellowing lower leaves.
3. White roots Roots visible at the bottom of the pot should be white. Brown or blackened roots mean damage. A rootball you can crumble slightly is better than one wound solid.
4. The runner scar still there The cut mark where the runner joined the parent plant is on one side of the crown. That scar sets the planting orientation, so choose plants where it has not been trimmed off.
5. No black spots on the leaf stalks Sunken black spots an eighth to a quarter of an inch across on the leaf stalks or the runner scar mean anthracnose. The plant will die after planting, so avoid not just that plant but everything on the same bench.

Do not bury the crown, and do not leave it proud

Planting too deep is the commonest mistake by far. Bury the crown and new leaves cannot get out, it rots in the damp, and you lose the plant. What you want is the upper half of the crown visible above the soil, with soil only over the roots.

Too shallow is no better: exposed roots dry out and frost heave lifts them, so the plant never establishes. Set the plant so the bottom of the crown is level with the soil surface, and firm the soil around it.

1. Dig only as deep as the rootball Dig deep and backfill and the plant sinks later, burying the crown. Digging exactly to the depth of the rootball is more reliable.
2. Match the heights Set the shoulder of the rootball level with the surface of the bed. Not putting fresh soil on top of the rootball is, in practice, the whole technique.
3. Firm around the outside Push soil into the gaps and press only around the outside of the rootball with your fingers. Pressing down on the middle of the plant sinks it.
4. Water thoroughly, but only on planting day Water gently at the base until the compost and the bed soil have knitted together. After that water only when dry rather than keeping the soil constantly damp.

Watering settles the soil and the crown can end up buried a week later. Check the height again about a week after planting and draw soil away if needed.

Face the runner scar towards the path

A strawberry throws its flower trusses on the side of the crown opposite the runner scar. Plant with the scar facing into the bed or towards the wall and the fruit hangs out over the path, where picking and checking are easy.

The benefit is not only in picking. With all the fruit facing one way it is easy to lift onto the mulch, which cuts soil splash and gray mold. Plants facing random directions leave fruit hidden under leaves where you miss it.

1. Find the scar before you plant Before you tip the plant out of its pot, look right around the side of the crown for the thin cut stem. Brush the compost away with a finger if it is hidden.
2. In a double row With two rows on one bed, face the scars towards the center of the bed. The trusses on both rows then hang outwards over the paths.
3. In a container Face the scar towards the middle of the pot so the fruit hangs over the rim. Fruit that touches neither soil nor leaves suffers far less gray mold and slug damage.

If you cannot find the scar, look at how the leaf stalks fan out. The trusses come out on the open side of the fan.

The bed and the soil

Strawberries prefer slightly acid soil and dislike heavy liming. A pH of 5.5 to 6.5 suits them, so unless your soil is strongly acid, go easy on lime. Keep the base fertilizer modest as well: too much nitrogen gives you leaf instead of flowers and brings on powdery mildew.

Make a raised bed eight to twelve inches (20 to 30 cm) high, two feet (60 cm) wide for a double row, with plants 10 to 12 inches (25 to 30 cm) apart. Raising the bed keeps the roots out of winter wet and keeps the fruit clear of the ground in spring.

Lay black plastic mulch only in early winter, once cold has firmed the plants up. Laid in autumn it warms the soil too much, dormancy is incomplete, and spring growth comes away unevenly.

June-bearing or everbearing

Plants are sold as June-bearing, a trade term for short-day types that crop once in late spring, or everbearing, which crop on and off from late spring to autumn. Their calendars are completely different, so check the label before you buy. Everything above assumes a June-bearing variety. The name comes from the northern hemisphere; the crop arrives in late spring wherever you are.

Everbearing types keep flowering across a wide temperature range, but each berry is smaller and hot weather brings misshapen fruit through poor pollination. Choose everbearing for a long trickle and for containers, and June-bearing types for large, sweet fruit.

Everbearing varieties dislike heavy feeding and wet soil. Overfeed and you get leaves and no fruit, so feed weakly and more often.

Containers and hanging baskets

A trough needs to be at least eight inches (20 cm) deep, and a 26 inch (65 cm) trough takes two plants at most. Crowded, the air does not move and the fruit is lost to gray mold. Ordinary vegetable compost is fine, but put drainage material in the bottom.

Hanging baskets and strawberry planters keep the fruit off the ground, so disease and slug damage are both lower. They hold little compost and dry fast, so while the fruit is swelling they need watering daily. In winter the opposite applies: water sparingly, but do not let them dry out completely.

Roots in containers freeze easily. In the coldest weeks move pots against a wall or under an overhang. Frozen compost means the plant cannot drink, the leaves crumple, and spring growth is late.