Sunday, April 14, 2013
Lesser Celandine: Scourge of Flood Zones or Erosion Controller?
The yard of a friend is being inundated by lesser celandine, Ranunculus ficaria (see above from the infested Bartram's Garden in Philly). My friend has conducted a multi-year assault on this plant, trying to reduce its numbers, but with little luck. And here is why: it is a very vigorous grower, a non-native invasive perennial. It produces abundant, tiny, cream-colored bulbets after flowering (which it is doing now) in early spring. It has multiple finger-like tubers that you can can see when you pull the plant up, often leaving some of the tubers below ground, which then re-sprout. If you do carefully pull or dig this plant, all the tubers and bulbets must be removed and the plant bagged for trash. There are no bugs or animals that will eat this plant to keep it in check. Lesser celandine inhabits flood plains and riverine habitats.
I like the advice of Mike McGrath of "You Bet Your Garden" on WHYY in Philadelphia: http://whyy.org/cms/youbetyourgarden/
McGrath says there are two feasible strategies with lesser celandine: 1. Let it be. Lesser celandine is pretty good at controlling soil erosion and this is good thing in the flood plains it inhabits. Of course, if you let it be, eventually this is all you have. 2. Compartmentalize: define flower bed areas in your yard. In these areas, work hard to remove all lesser celandine, shifting the top few inches of soil to another area of your yard if you have to, and bringing in new soil. Then, create a barrier- use at least 2 in deep edging (even deeper is better) around this bed. I would, for about a foot around the bed, install brick pavers with a barrier underneath. Wait a few weeks to see if more celandines sprout in the bed and remove them. Then you can plant, but you must be vigilant to make sure no new celandine seedlings take hold.
By the way, don't mistake lesser celandine for the non-invasive, charming celandine poppy: