Here's a super random question: might the tubers be poisonous to ducks ? I'm not sure if I just discovered a brilliant way to get rid of lesser celandine, OR accidentally kill mallard ducks, OR if it doesn't kill them, might I be inadvertently causing the LC to spread via the ducks digestive track not "composting" them properly... I just put a big pile of LCelandine into a hole I dug in the center of my compost heap and before I got around to covering it up to let the heat digest them into oblivion, there were 2 Mallard Ducks pecking away at the pile. I don't know if it was a coincidence that there was something else mixed in with the tubers & greens that they were noshing on or if it was the tubers themselves. I know it's a shot in the dark, but any thoughts? Should I cover the heap? Or let them continue to go at it?

Try this one- got it from a website that I can't go back to for some reason: Lesser celandine Ranunculus ficaria L. Buttercup family (Ranunculaceae) Download PDF version formatted for print (174 KB) -------------------------------------------------------------------------------- NATIVE RANGE Europe DESCRIPTION Lesser celandine, also known as fig buttercup, is an herbaceous, perennial plant. Plants have a basal rosette of dark green, shiny, stalked leaves that are kidney- to heart-shaped. The flowers open in March and April, have eight glossy, butter-yellow petals, and are borne singly on delicate stalks that rise above the leaves. Pale-colored bulblets are produced along the stems of the above-ground portions of the plant, but are not apparent until late in the flowering period. When in bloom, large infestations of lesser celandine appear as a green carpet with yellow dots, spreading across the forest floor. There are many varieties of lesser celandine including a double-flowered form with many crowded petals and dark green leaves mottled with silvery markings. NOTE: Lesser celandine closely resembles marsh marigold (Caltha palustris), a native wetland plant that occurs in the eastern United States. Marsh marigold is a robust plant with glossy, rounded or kidney-shaped leaves and flowers on stalks that are 8 in (20.3 cm) or more in height and consist of five to nine deep yellow "petals" (actually sepals). Marsh marigold does not produce tubers or bulblets, nor does it form a continuous carpet of growth. Extreme care should be taken to correctly identify lesser celandine before undertaking any control measures to avoid impacts to this plant. ECOLOGICAL THREAT Lesser celandine is an exotic spring ephemeral and a vigorous growing groundcover that forms large, dense patches on the forest floor, displacing and preventing native plants from co-occurring. The ecological impact of lesser celandine is primarily on the native spring-flowering plant community and the various wildlife species associated with them. Spring ephemerals complete the reproductive part of their life cycle and most of their above-ground development before woody plants leaf out and shade the forest floor. Native spring ephemerals include bloodroot, common and cut-leaved toothwort, Dutchman's breeches, harbinger-of-spring, squirrel-corn, trout lily, Virginia bluebells, and many others. Because lesser celandine emerges well in advance of the native species, it can establish and overtake areas rapidly. DISTRIBUTION IN THE UNITED STATES Lesser celandine is currently found in nineteen states in the Northeast and Pacific Northwest (USDA PLANTS map). It is reported to be invasive in nine states (Connecticut, Delaware, Maryland, New Jersey, Oregon, Pennsylvania, Virginia, Wisconsin, West Virginia), and the District of Columbia (WeedUS Database). HABITAT IN THE UNITED STATES Lesser celandine occurs in moist forested floodplains and in some drier upland areas, and seems to prefer sandy soils. BACKGROUND Lesser celandine was introduced to the United States as an ornamental plant. It is still available commercially in the U.S., along with many colorful varieties. All varieties of lesser celandine should be assumed to be invasive. BIOLOGY & SPREAD Lesser celandine is an exotic perennial plant and spring ephemeral that spends much of the year (summer through early winter) underground as thickened, fingerlike tubers or underground stems. During the winter, leaves begin to emerge and photosynthesize in preparation for flowering. Flowering usually occurs from late winter through mid-spring (March through May), depending on conditions. Afterwards, the above-ground portions die back. Lesser celandine spreads primarily by vegetative means through abundant tubers and bulblets, each of which is ready to become a new plant once separated from the parent plant. The tubers of lesser celandine are prolific and may be unearthed and scattered by the digging activities of some animals, including well-meaning weed pullers, and transported during flood events. MANAGEMENT OPTIONS Lesser celandine is very difficult to control but it can be managed with persistence over time using methods that are site appropriate. While manual methods are possible for some (small) infestations, the use of systemic herbicide kills the entire plant tip to root and minimizes soil disturbance. Biological No biological control agents are currently available for lesser celandine. Chemical The window of opportunity for controlling lesser celandine is very short, due to its life cycle. In order to have the greatest negative impact to celandine and the least impact to desirable native wildflower species, herbicide should be applied in late winter-early spring (March through May). Apply a 1.5% rate of a 39 to 41% glyphosate isopropylamine salt (e.g., Rodeo for wetland areas) mixed with water and a non-ionic surfactant to foliage, avoiding application to anything but the celandine. Glyphosate is systemic; that is, the active ingredient is absorbed by the plant and translocated to the roots, eventually killing the entire plant. The full effect on the plant may take 1-2 weeks. Applications can be made during the winter season as long as the temperature is above about 50 degrees Fahrenheit, and no rain is anticipated within 12 hours. Because glyphosate is non-specific, spray should be controlled such that it touches only lesser celandine and does not drift onto desirable plants. To minimize impacts to sensitive-skinned frogs and salamanders, some experts recommend applying herbicide in March and then switching to manual methods.

This plant is a pain and the window of time in which to address it during any given year is limited. See the attached link. You would probably have to go chemical to knock it back significantly. Here is a link that might be useful: PCA fact sheet

What nice lively comments, just to add more information, I took over a nasty, neglected patch, next to ours, after our garden neighbour quit. Her version of "organic gardening" consisted of doing very little in general, tearing up existing stone slaps ( you do know that square elements do give off negativ vibes-kind of style), plucking flowers occasionally and starting and failing with one attempt at a raised bed, all in all for about 8years. potential new tenants looked at it, and all 4 said thank you, and then there came no others, so in order to spare us a rioting feast of blackberry, bindweed, goldenrod etc, we applied for it and got it. so the whole place is a clean slate, regarding nice plants. We are not allowed to use any chemical sprays in our plots, so round up would not be an option. Right now, I have very little time to spare ( moving to a new flat in 6 weeks, juggeling 2 kids and a newly started small business of mine along with 2 allotments, dh working plus studying), so I went for the smothering to get some peace of mind. The celandine emerge right NOW, and it seemed important to me to fix it now, otherwise I had to do something about them reseeding, spreading...later on. We had the sheet thing going for most of the alottment for a whole season, hand weeding the nastiest spots befor covering, in 2015. in 2016 I grew green manure and dug two new beds. so after 2 h of leveling, hoeing around the edges and spreading the black plastic, it was done. I have existing beds edged with longish cement slaps /(stones?) so that made it a lot easier. I'm glad because now I can focus on some remaing "bald" patches, dig them, plant lawn seeds near the apple tree and start some more beds on others. here some pics the nasty hybrid bluebells were every where but we got rid of most of them, found some more today, so thanks a bundle, a great garden start to you all, bye, Lin That's work in progress Done, oh, and that's agricultural stuff, really resilient plastic for "silage", fermenting grass... From another angle