- Creeping cinquefoil is the low, flat weed with leaves split into five toothed leaflets and small yellow flowers, and it throws out long runners that root every few inches and shrug off most lawn weedkillers.
- The way to beat it is by hand: lift and bag the runners before you mow so the blades do not chop and scatter them, then fork out each clump deep enough to take the whole taproot.
- It only gets in where the grass is thin, so reseeding the bare patches and feeding the lawn is what keeps it from creeping back.
The Weed That Shrugs Off Lawn Weedkiller
You spray it, wait a fortnight, and it is still there. That is the moment most people meet creeping cinquefoil properly, having assumed any lawn weedkiller would see it off. It will not. This is a weed built to spread sideways and survive, and the bottle in the shed is close to useless against it. The good news is that it has an obvious weakness, and once you know what it is you can clear the weed for the price of an hour’s work and a bag of grass seed.
The trick is to stop treating it like a weed you kill and start treating it like a plant you physically remove, root and runner. Pull that off and keep the grass thick afterwards, and it does not come back.
What You Are Actually Looking At
Creeping cinquefoil sits low and flat, rarely more than 20cm (8in) tall, and spreads outward rather than upward. Each leaf splits into five toothed leaflets, which is where people mix it up with a wild strawberry or a buttercup. Through summer it carries bright yellow flowers with five petals, roughly 2cm across, from about June to September, so by autumn the flowers are fading and what you see is a creeping mat of leaves. The giveaway is the runners: long, thin stems that snake out across the turf and push down roots wherever a node touches soil. Under each established plant sits a dark taproot that can reach about 30cm (1ft) down.
It takes hold where the grass has already thinned. Cinquefoil copes with dry, poor soil that grass struggles in, and it races to fill any bare or worn patch before the turf can. Every runner that roots becomes a new plant, every scrap of taproot left in the ground can regrow, and it sets seed on top of all that. Three ways to spread from one plant is why a small patch becomes a wide one in a single season, and why half a job leaves you back where you started.
Why the Spray Bottle Lets You Down
The Royal Horticultural Society is blunt about chemicals here: “Creeping cinquefoil is resistant to many selective lawn weedkillers.” A selective weedkiller is the type sold to kill broadleaved weeds while sparing grass, and cinquefoil simply tolerates it. Stronger total weedkillers would kill the grass around the weed as well, which hands you bare soil, exactly the opening cinquefoil wants. So the spray either does nothing or makes the problem worse.
That leaves the method the RHS does back, which is lifting the plant out by hand. It takes more effort than spraying, but it works, costs almost nothing, and puts no poison on a lawn that children or pets use. Early autumn is a good time to do it: the soil is damp and soft so taproots slide out whole, and the grass is still growing enough to knit over the gaps you leave behind.
Lift the Runners, Then Dig Out the Root
Start before you mow, not after. Rake firmly over the patch to lift the creeping runners and any flowering stems up off the turf, then cut and gather them, or go over the area with the mower box on to collect them. The order is the whole point here: run a mower straight over cinquefoil and the blades chop the runners into rooted fragments and fling them across the lawn, seeding new plants as you go. Lift first, bag the pieces, then mow.
Now take out the clumps. Push a border fork or hand fork in beside each plant and lever up the whole root, going deep enough to bring the full taproot with it, as any length left behind can resprout. A long-handled taproot weeder, the kind sold for dandelions, lifts the root with far less digging and costs about £6 to £12 (around $8 to $16); a border fork runs about £10 to £18 (around $13 to $24) from B&Q, Wickes, Screwfix, Amazon or the equivalent aisle at Home Depot and Lowe’s. Work along the runners too, lifting each rooted node with a hand fork. The job feels fiddly, but every root and node you remove is a plant that will not return.
Do not drop the pullings on the compost heap. A home bin rarely runs hot enough to kill cinquefoil runners, taproots or seed, so a composted plant comes back through your beds later. Bag the lot for council green waste or take it to a recycling site. Then reseed the bare patches you have opened up, firming fresh grass seed into the soil and watering it until it takes, so the gaps close with grass rather than the next weed.
Close the Gaps So It Cannot Come Back
Clearing the weed is half the job. The other half is making the lawn a place cinquefoil cannot get a foothold, and that comes down to one thing: thick grass leaves it no bare ground to root into. Overseed thin and worn areas with a hardwearing grass mix, about £10 to £20 (around $13 to $25) a box, and keep the new grass watered until it establishes. Feed the lawn in autumn with a potassium-rich lawn food so the turf thickens and hardens for winter rather than thinning out.
Lift the mowing height a notch as well. Grass cut too short thins and weakens, and thin grass is the opening cinquefoil waited for in the first place; a slightly longer sward shades the soil and crowds the weed out. Where the ground is dry and poor, which is the condition cinquefoil likes best, a light top dressing of loam worked in over a season improves it enough to tip the balance back to the grass. Keep the turf dense and growing, check the worn edges each autumn, and the weed that beat your weedkiller never gets the bare patch it needs.
