Creeping Cinqefolia

Sorry to hear you are plagued with this pest. It is pretty difficult to eradicate, but much depends on your soil. If you have a heavy clay, for once you may be better off, as the roots don’t penetrate so far down.

So, if your soil is heavy  you probably don’t need to dig everything up, but go over the top few inches with a hand fork and trowel at one of the rare times when the soil is nice and damp and workable, dig up the crowns of the many cinquefoil plants and pull out as much of the root and runners as you can. Keep an eye on it and if you see little plants reappearing, go over it again.

If your soil is light, however, you probably will do best to dig up your herbaceous plants and dig the whole bed over, removing every scrap of cinquefoil you can find, and pulling it out of the roots of the shrubs. Obviously you need to do this either in spring, when the cinquefoil will probably get going before your plants, or in the autumn, when everything is winding down but you can still see where the cinquefoil is.

Either way you won’t get rid of it all, but it will give you a good head start, and vigilance afterwards, pulling out any bit that shows its head, should allow you to keep on top of it.

Even if you can use it safely around your plants, weedkiller tends not to be very successful with this as it doesn’t pass easily through the thin runners. However, if you have taken your plants out in the spring and have somewhere to store them for a while, you can give any cinquefoil which reappears a blast of weedkiller – kick it while it’s down! – before you put them back, but only use glyphosate or something that doesn’t leave residue in the soil…

Good luck!