Lesser celandine: An attractive spring weed that spreads with a vengeance
Also known as fig buttercup, lesser celandine forms dense mats that outcompete other plants and is adapted to many growing environments.
Last week, two homeowners brought in a weed I had not seen before, and neither had they. It came in from a neighboring yard and established itself in an area of ground that was wet from flooding. It is now overtaking many areas of their landscape, including beds with Hostas and spring ephemerals. The weed crept over the ground, forming a dense mat of small (0.5–1 inch), green, kidney-shaped leaves and bright yellow, eight-petal flowers that resemble buttercups, but with more pointed petals. When the mat of foliage and roots was teased apart, there were a number of tubers present in the sample. After looking at it more closely and consulting some references, I was able to identify it as lesser celandine (Ficaria verna), a member of the buttercup family formerly known as Ranunculus ficaria.
Lesser celandine, also commonly known as fig buttercup, is an attractive plant, and it is easy to see why it was originally brought over from Europe as an ornamental. However, despite its good looks, it is a serious garden thug. It forms thick mats that choke out any competitors and spreads aggressively. Unlike some other plants, it thrives in all light conditions, from full sun to dense shade, and grows in all kinds of soils from wet to dry.
Because it comes up so early in the season, it gains an additional competitive advantage over other plants. It is particularly troublesome in wooded areas with spring ephemerals, which it easily outcompetes and displaces. Being an exotic plant, it does not have any established natural enemies that help to keep it in check.
Although it is not listed as an invasive species in Michigan, it is listed as such in several other states. It can be found on a Plant Conservation Alliance “Least Wanted: Fig Buttercup” poster. The poster gives recommendations for its control. Eliminating it can be difficult, in part because it emerges early in the season and goes dormant over summer, giving a relatively short window for control.