Moss taking over garden bed

Asked May 4, 2017, 8:07 PM EDT

This small plant, which I think is a type of moss is taking over my gardens. It is different than the moss that grows on rocks here. Its been growing for a few years and despite weeding it keeps reproducing. Is there a way to get rid of it without using chemicals?

Multnomah County Oregon

1 Response

Thank you for attaching the excellent image of your weed. This is not moss, but a look-a-like weedy plant called pearlwort, Sagina procumbens. Pearlwort spreads by rooting at the stems and by a multitude of extremely tiny seeds. By the time pearlwort is in flower, it’s also producing seeds! Worse yet, pearlwort is able to set seed and sprout from April through September!

You can decrease the pearlwort population if you remove every seedling as soon as you see it and definitely before the plants bloom and set seed. (Notice the small enlargements at the tips of the branches in the image I attached; they’re flower buds.) The complication which will require your persistence for several years is that many dormant seeds from previous years are waiting for their chance to sprout.

If you decide to use an herbicide (weedkiller), realize that glyphosate can be used safely if painted on individual plants. Glyphosate is the active ingredient in various home garden herbicides such as Roundup; see the label for directions. “Painting” the weed eliminates the need to spray and, thus, protects nearby plants. Just as with hand removal, you must act before the plants set seed, preferably before they set buds.