How do I make new strawberry plants from runners?

Strawberry plants crop heavily for about three years and then decline sharply, so a bed left alone gets worse every season. The plants solve this themselves by producing runners, and all that is needed is to direct that process: choose which plantlets root, root them into pots so they can be moved cleanly, and refuse to propagate from anything that looks unhealthy, because strawberry viruses travel down runners.

What you'll need

• 9cm pots
• Multipurpose compost
• Wire staples, hairpins or small stones
• Secateurs or scissors

Step by step

1. Choose the parent plants deliberately.Only from plants that cropped well this year and show no mottling, crinkling, stunting or yellowing. Virus and eelworm both travel down runners, and propagating from a poor plant multiplies the problem.
2. Wait until the main crop is finished.Runners appearing during fruiting divert energy from the fruit, so remove them then. Once picking is over, in July and August, let the plant produce runners and use them.
3. Sink a pot of compost beside the parent.A 9cm pot filled with multipurpose compost, buried so the rim is level with the soil surface. The sunken pot means the new plant can be lifted later with its roots intact and no check.
4. Peg the first plantlet onto the compost.The first plantlet along each runner is the strongest. Sit it on the compost with its crown at surface level, not buried, and hold it with a wire staple, a bent hairpin or a small stone.
5. Leave the runner attached to the parent.It is feeding the plantlet while roots form. Cutting it now leaves an unrooted piece that will die.
6. Cut off the rest of the runner beyond the plantlet.Everything past the first plantlet is diverting energy. Trim it back so the parent supports one strong new plant per runner rather than four weak ones.
7. Keep the pots watered.A small pot of compost in summer dries out fast. Water the pots as well as the bed, or the plantlet never roots.
8. Sever after four to six weeks, once it has rooted.Test with a gentle tug: resistance means roots. Cut the runner close to the new plant, leave it in place for a few more days, then lift the pot.
9. Plant out in early autumn, or grow on and plant in spring.September planting gives the biggest crop next summer. Plant with the crown exactly at soil level, 35–45cm apart, in ground that has not grown strawberries recently.
10. Run the bed on a three-year rotation.Replace a third of the plants each year with new runners, so no plant is over three years old and the bed never collapses all at once.
11. Clear old foliage after fruiting each year.Cut the old leaves off about 10cm above the crown once picking ends, remove the straw, and clear the debris. It removes disease and encourages new growth for next year.

Tips

• Runners can also be pegged directly into the soil, but potted ones transplant with no root disturbance, which matters if you are moving them to a new bed.
• Take more runners than you need. Not all root well, and spares are welcome.
• Perpetual (everbearing) varieties produce fewer runners than summer-fruiting ones, so plan on buying replacements more often.
• Never replant strawberries into ground that has just grown strawberries. Move the bed to break the cycle of soil-borne problems.
• Buy in certified virus-free stock every few years to refresh the line, rather than propagating indefinitely from the same plants.

Common mistakes

• Taking runners from tired or mottled plants — Virus, eelworm and vine weevil all travel with the plant. A weak parent produces weak offspring and spreads the problem to a new bed.
• Cutting the runner before the plantlet has rooted — It has no root system of its own and depends on the parent. Wait for resistance to a gentle tug.
• Burying the crown of the new plant — A buried strawberry crown rots. It sits exactly at soil level, the same rule as when planting a bought plant.
• Letting every runner root where it lands — The bed becomes a dense mat of overcrowded plants that fruit badly and hold damp around the fruit. Direct a few, remove the rest.

Questions people ask