Cheerful yellow flowers adorn mats of shiny heart-shaped green leaves in various areas of my yard right now. Much as I have looked forward to spring after this long winter, I am not happy to see these invaders in my yard! This is the invasive weed known as Lesser celandine or Fig Buttercup, Ranunculus ficaria.
Lesser celandine can be identified not only by its basal rosette of heart-shaped leaves , but also by the light tan stem bulblets that can be seen along the stem after flowering. In addition, tubers on its roots are plainly visible when the plant is dug up. The flowers are held above the leaves on a naked stem, and they are yellow with 3 green sepals and 7 to 12 yellow petals. This is a perennial spring ephemeral whose leaves will disappear by June only to reappear the following winter.
Lesser celandine, native to north Africa and Europe, was probably introduced to the United States as an ornamental plant. The problem with this plant is that it tends to cover large areas and competes with native spring ephemerals such as Virginia bluebells, Dutchman’s breeches, trout lilies and others for space and nutrients. It is an aggressive plant that spreads not only by seeds, but also vegetatively via its root tubers and stem bulblets. This makes it particularly difficult to eradicate from an area since it is hard to remove all parts of the plant, and, in fact, weeding can inadvertently spread the plant! The bulblets and seeds can also be dispersed by rodents and other animals.
Small stands can be controlled by vigilant mechanical weeding, but be sure to bag up all bulblets and root tubers for disposal. Each tuber or bulblet left behind can give rise to another plant! Chemical control involves the use of glyphosate which should be applied in late winter to early spring (March-May) on days when the temperature is above 50 degrees. Later in the season, the nonselective glyphosate may remove other desirable native plant species. If near wetlands, be sure to use a wetland-approved glyphosate product, and, of course, follow instructions carefully. This website gives more information about this plant:
Lesser celandine can be confused with our desirable native marsh marigold Caltha palustris . This native, also a member of the buttercup family, does not have tubers on its roots or bulblets along its stem, and its flowers are a bit different. It forms solitary clumps rather than large mats. This website compares the two:
I have a question. After I have applied glyphosate to the Ramunculus ficara what do I do next to the ground and garden that now has dead spaces or partially dead weed?
Can I compost over and plant there again this season? Should I just compost or mulch and wait to replant next year?
I'd value your recommendation.
Glyphosate doesn't have soil activity. In other words, plants can't absorb it through their roots. It only affects them if it's sprayed directly on their foliage where it is absorbed and spreads systemically through the plant. It can sometimes take several weeks for it to kill the plant it is sprayed on, but replanting in the area can occur almost immediately, often within a few days. How soon you can replant depends on the product you used and what ingredients it contained. The label should state what that time is. With that being said, you still may get regrowth of lesser celandine next season because of any bulblets that were loose in the soil of the area since the glyphosate wouldn't have killed them, so it can take several seasons to get rid of it totally. If you plant perennial plants in that area, be sure to protect them if you have to spray glyphosate again next year or spray before their foliage comes up. I hope this answers your question?