If you grow strawberries, you've probably watched your plants throw out long, wandering stems in high summer, each one carrying a little plantlet at its tip. Those are runners, and far from being a nuisance, they're one of the most generous gifts the fruit garden hands you. With a bit of patience you can turn them into a whole new bed of healthy plants, completely free, and identical to the parents you already love. Here's exactly how I go about it.
What are runners, and why do strawberries send them out?
A runner, or stolon to give it its proper name, is a slender horizontal stem that grows out from the crown of the plant. As it stretches across the soil it produces baby plantlets at intervals along its length, each with the makings of its own leaves and roots. It's the strawberry's way of colonising ground around itself, spreading sideways to claim new territory while the parent stays put.
The clever part, from a gardener's point of view, is that these plantlets are clones. Because they're produced vegetatively rather than from seed, every one is genetically identical to the plant it came from. That means the flavour, the cropping habit, the disease resistance, all of it carries straight through. Raise strawberries from seed and you get a lottery; raise them from runners and you get exactly what you started with.
When do runners appear?
The main flush comes through summer, generally once the plant has finished or is finishing its fruiting. The plant pours its energy into flowering and cropping first, then turns to spreading. By midsummer to late summer you'll usually have plenty of runners to choose from, which gives the new plantlets time to root and establish well before the colder months close in.
One small caveat. If your plants are still young or you want a really heavy crop, it's worth snipping runners off through the growing season so the plant concentrates on fruit rather than offspring. But when you do want new stock, just let them run.
Choosing which runners to take
This is the step people skip, and it's the one that matters most. Only ever propagate from vigorous, healthy parents. Look for plants that have cropped well, with clean, glossy foliage and no sign of mottling, distortion, yellowing or wilting. Strawberries are prone to viruses that build up invisibly over time and pass straight down the runner, so a sickly-looking parent simply hands its troubles on to the next generation.
On each runner, the plantlet closest to the parent is usually the strongest, as it gets first call on the parent's resources. I tend to use the first one or two plantlets along a runner and ignore the rest. As for how many to take per plant, three or four good runners from a healthy plant is plenty; take more and you exhaust the parent and end up with weedy little plantlets that struggle.
Two methods: peg down, or detach and pot
There are two reliable ways to do this, and I use both depending on how organised I'm feeling.
The first, and the one I'd recommend if you want the best results, is to peg the plantlet down while it's still attached to the parent. Sink a small pot, around 8 to 9cm, filled with multipurpose compost into the soil right beneath a chosen plantlet, or simply stand it on the surface nearby. Settle the plantlet onto the compost so its base sits in contact with it, then pin it in place. While it's still joined to the parent it keeps drawing water and nutrients across the runner, which means it roots quickly and rarely checks. It's the strawberry equivalent of layering.
The second method is to detach the plantlet and pot it up on its own. This is handy if the parent bed is a tangle or you want to tidy things up in one go. Sever a plantlet that's already showing the first signs of its own roots, pot it into compost, water it well and keep it somewhere sheltered and lightly shaded until it takes hold. It works perfectly well, but you'll need to baby it a little more in the first week or two because it has no parent to lean on.
The pinning technique
For the peg-down method you just need something to hold the plantlet firmly against the compost so it doesn't lift. A bent piece of galvanised wire, an opened-out paperclip, or a small landscape staple all do the job. Hook it over the runner just behind the plantlet, not through the crown itself, and press it in so the base of the little plant is snug to the surface. Keep the compost moist and you should see fresh roots within a couple of weeks.
When do I cut it free from the parent?
Don't rush this. Give the pegged plantlet two to four weeks to root properly, then give it a very gentle tug. If it resists and feels anchored, it has rooted and you can snip the runner connecting it to the parent. I cut close to the new plant and tidy the rest of the runner away afterwards. After severing, leave the youngster in its pot to carry on growing rather than disturbing it straight away.
Potting on and overwintering
Once a plantlet is rooted and growing as its own plant, you can either plant it into its final position or, if it's late in the season, pot it on and grow it through the winter to plant out in spring. Young plants in pots come through the cold months best in a cold frame, an unheated greenhouse, or simply tucked against a sheltered wall. Keep them just moist, never waterlogged, and protect the pots from the worst freezes. Come spring you'll have sturdy, well-rooted plants raring to crop.
The three-year refresh cycle
Strawberries don't go on forever. Plants are usually at their best in their second and third years, after which cropping tails off and they accumulate more disease. My habit is to refresh the bed on a rolling cycle, replacing the oldest plants roughly every three years using runners taken the previous summer. Stagger it, take runners from your strongest plants each year, and you'll always have productive young stock coming through without ever buying in.
That said, there's a place for bought plants too. Certified disease-free stock from a reputable supplier is the cleanest possible start, particularly if you're setting up a brand-new bed or your existing plants have picked up a virus. But for keeping a healthy patch going year after year, runners from your own good plants are honestly hard to beat.
So next time your strawberries start sending out those questing little stems, don't reach for the secateurs straight away. Peg a few down, give them a few weeks, and you'll have a fresh generation of plants for nothing. It's one of the most satisfying jobs in the summer garden. Happy growing. — Ash
Why some runners come out thin and weak (and how to fix it)
Thin, wiry runners with small or slow-rooting plantlets almost always mean the parent plant is short of resources, not that anything's wrong with the runner itself. A strawberry plant is putting energy into three jobs at once in July and August — ripening any late fruit, building next year's crown, and throwing out runners — and if it's underfed or has dried out at any point that summer, the runners are usually what gets shortchanged first.
Before blaming the variety, check the basics. Has the bed dried out at the roots in the past few weeks? Strawberries are shallow-rooted and wilt fast in a dry spell, and that stress shows up in the next runner as much as in the leaves. Is the parent plant three or four years old and due for replacement anyway? Older, tired crowns send out noticeably weaker runners than a plant in its first or second productive year. And has it been left to carry a heavy crop right through fruiting with no feed at all? All three push the plant into survival mode, and runners are the first thing it skimps on.
The fix is a potassium-rich liquid feed — the same tomato feed you'd use on fruiting tomatoes works well — applied every 10 to 14 days from when the first runners appear until you've pegged down the ones you want. Keep the compost around the parent's roots consistently moist rather than letting it swing between dry and sodden; that alone often turns the next flush of runners from wiry to properly thick within a couple of weeks. If you're propagating from a plant that's also still fruiting heavily, it's worth accepting a slightly smaller crop that year in exchange for stronger runners — you can't really have maximum fruit and maximum propagation from the same plant at once.
Does it matter which plantlet on the runner I choose?
Yes — the first plantlet, the one closest to the parent, is reliably the strongest and roots fastest. A single runner often produces two or three plantlets strung out along its length, and the second and third ones are noticeably smaller with thinner root initials because they're further from the parent's energy supply. If space allows, peg down the first plantlet on each runner and snip the runner off just beyond it rather than trying to root all three — you'll get one good plant instead of three mediocre ones, and you can always take more runners later in the season for the rest.
What potting mix should I use for pegging down runners?
A standard peat-free multipurpose compost works for pegging plantlets straight into small 9cm pots sunk into the bed, but it holds too much water on its own for reliable rooting — mix in around one part perlite or horticultural grit to four parts compost. That extra drainage matters more than the compost itself: waterlogged compost around an unrooted plantlet tends to rot the base before roots form, especially if you get a wet spell in August. Sink the pot so its rim sits level with the soil surface, so the plantlet isn't sitting proud and drying out faster than the bed around it.
Can I feed a runner while it's still attached to the parent?
Yes, and it's worth doing — feeding the parent plant during the pegging-down period feeds the runner too, since the connection stays alive until you sever it. There's no need to feed the plantlet's own pot separately at this stage; a liquid feed watered onto the parent's roots every 10 to 14 days is enough to carry through the runner and support the plantlet while it's building its own root system.
