Plant of the Month: Creeping Buttercup
Creeping Buttercup (Ranunculus repens) is keeping me very busy weeding our garden this spring. A pretty little perennial, native to Europe, Asia, and North Africa, creeping buttercup has been introduced and become naturalized in nearly every state in the United States. Left to its own devices, creeping buttercup sends out creeping stems that take root at the nodes when they touch the ground, forming a dense carpet that shades and crowds out more desirable plants.
Keep creeping buttercup mowed in your lawn and you’ll have a deep green groundcover, soft underfoot, that sprinkles glossy yellow flowers all over your landscape. Leave it unshorn and the foliage grows to nearly a foot tall, with flower stalks that rise even higher. It’s a shame this non-native is so invasive because it’s really quite pretty.
Recognize creeping buttercup, and sort it out from the many native buttercups, primarily by the way its creeping stems spread. The entire plant is somewhat hairy, including the flower stems and leaves. The leaves, divided into three leaflets, usually have irregular white splotches on the upper surface. The shiny yellow blossoms have 5-7 petals.
Creeping buttercup prefers moist, acidic soil. That’s something we have in abundance on our property and it’s quite common throughout the Pacific Northwest on the wet side of the Cascades. It will grow in both full sun and rather deep shade.
This spring I’ve dug many wheelbarrows full of creeping buttercups from our flower beds and vegetable garden. We have a couple of shady areas that we’re converting into moss gardens, and I’ve been digging buttercups out of the moss, too. My favorite tool for digging buttercups is a Cobrahead weeder which I’ve had for several years. This tool lets me dig under the fibrous root mass and free it from the surrounding soil. I’ve gotten quite proficient at thrusting the tool under a buttercup and pulling it out with my other hand. Other gardeners prefer different tools, including a hori hori. Fortunately creeping buttercup does not resprout from every tiny piece of root.
In addition to spreading by creeping stems, creeping buttercup also seeds around prolifically. That means keeping the flowers cut when you aren’t able to weed out all the plants. If you’re in the “OK to use glyphosate” group of gardeners, creeping buttercup responds very well to the herbicide, withering away to nothingness in a couple of weeks.
You might confuse creeping buttercup with our native western buttercup (Ranunculus occidentalis). From a distance they can look similar, but western buttercups lack creeping stems and don’t have white blotches on the leaves. Western buttercup leaves are also a little lighter green than creeping buttercups.
Creeping buttercup illustrates why all pretty flowers that grow outside of gardens are not “wildflowers.” Some of them are just plain weeds. I’d better go get my weeding tool and wheelbarrow and get back to work.
You can find more information about creeping buttercup, and other suggestions for controlling it, on the King County Noxious Weeds website.