Gadenin日本語Get the appWhen to cut runners and when to let them run
Around the end of picking, thin stems begin to run out from the base of the plant. These are the runners, and they produce young plants along their length. Strawberries are propagated from these rather than from seed.
Any runner that appears while you are still picking should be cut at the base, because it takes resources that would go into the fruit. Once picking has finished, stop cutting and let them run so you can raise plants.
| When | What to do with runners | Why |
|---|---|---|
| While picking | Cut at the base as you see them | They take resources from the fruit |
| End of picking | Stop cutting and let them run | To produce young plants |
| Midsummer | Root them into pots | Avoid damaging roots by lifting later |
| Late summer | Detach and grow on | In time for autumn flower bud formation |
Choosing the parent plants
The quality of your new plants is set by the parent. Mark the plants that stayed free of disease and cropped well with good flavor, and keep those as parents. Plants lose vigor with age, so change your parents every year.
- Mark them while you are picking Tie a piece of string or a label on the plants that crop well and taste good as you pick. By early summer you will not be able to tell which they were.
- Rule out the diseased ones Drop any plant that had a lot of gray mold, or leaves smaller on one side. Otherwise the problem travels into next year on the new plants.
- Work out how many you need One parent gives you roughly three to five usable young plants. Decide how many you want to plant and aim for about thirty per cent more.
Propagating from the same line indefinitely carries its diseases forward as well. Buy fresh plants every third year to renew the stock.
Why the first young plant is not used
The first young plant along a runner from the parent is the one that inherits most strongly from it, so if the parent was carrying disease, it gets the largest share. It also tends to grow too big, which delays flower bud formation in autumn.
So use the second and third instead. They are further from the parent, so less likely to bring disease with them, and they come more even in size. Beyond the fourth they are often not well enough developed, so in practice the second and third are what you use.
| Young plant | Position | Use it? | Why |
|---|---|---|---|
| First | Nearest the parent | No | Inherits disease most strongly |
| Second | Next along | Yes | Even in size and healthy |
| Third | Next again | Yes | Big enough by autumn |
| Fourth and beyond | Furthest out | If you need them | Often not well enough developed |
You do not use the first young plant, but you must not cut the runner there. Cut it and nothing beyond it develops.
Rooting the young plants into pots
Rooting into pots rather than into the bed is the single thing that most improves the quality of home raised plants, because the roots never get torn.
- Put the pot in place first Fill a three and a half inch (9 cm) pot with compost and set it directly under the young plant. Letting it root into the bed means cutting roots when you lift it.
- Bring the crown into contact Peg the runner down with a pin or a stone so the center of the young plant sits on the compost. Do not bury the crown, exactly as at planting.
- Line the pots up the same way Set the pots in a row with the parent side of the runner all facing the same way. That lines up the scars and makes autumn planting much quicker.
- When to detach It takes three to four weeks for roots to reach the bottom of the pot. Leave the runner attached until then.
- Where to cut Cut the parent side of the runner leaving about an inch (2 cm) attached. That stub is your orientation mark at planting time, so do not cut it flush.
Looking after young plants in late summer
Late summer heat and drought is when young plants are most easily lost. Keep the pots in half shade and water morning and evening. Do not use saucers, because the water standing in them gets hot during the day.
Feed only a dilute liquid feed every ten days or so. Stop feeding in early autumn and keep them on the dry side, which encourages flower bud formation. Fertilizer still in the plant at that point gives you a leafy young plant and no buds.
- Where to stand them Somewhere that gets morning sun only. Standing pots straight onto concrete overheats the compost from reflected heat, so raise them on a bench or a board.
- Watering Twice a day, morning and evening, until it runs from the bottom. If they wilt at midday, wait until evening rather than watering in the heat, which damages the roots.
- Stop feeding in early autumn Stop the liquid feed in early autumn. As the nitrogen level in the plant falls, flower buds form more readily, in time for planting out in mid autumn.