Lesser Celandine Can Destroy Gardens

Written by Greenwise Team
Published on May 1, 2019
Lesser Celandine

Beware of the yellow buttercup

It’s that time of year when you might be noticing some pretty yellow flowers blooming in your garden or lawn, but don’t be fooled. They have the power to destroy your garden. Seriously. We’ve been getting several calls asking us, “What’s that little yellow flower that just popped up in my garden?” Since May is Illinois Invasive Species Awareness Month, this is a good time to identify Lesser Celandine in your lawn or garden and start getting rid of it.

So, here’s what you need to know….

Lesser Celandine (Ranunculus ficaria) is from the Buttercup family and is a non-native invasive weed showing up in our area. Lesser Celandine has yellow blooms nestled into deep green heart-shaped leaves. It starts blooming in April or May and lasts for about a month. The good news is it completely disappears in June. The bad news is it can spread aggressively and get worse the longer it’s in your lawn or garden. The roots are tuberous, and Lesser Celandine spreads by seed, too. The Chicago Botanic Garden in Glencoe advises removing Lesser Celandine “as soon as possible, including all cultivars, and/or do not add to collection in the future.”

It’s so pretty, why do I care that it’s in my garden?

Lesser Celandine is an innocent-looking flower, but because it’s so aggressive, it can suppress your other spring flowers from blooming, like your Bleeding Hearts, Virginia Bluebells, and Trillium. Think of it as the new Garlic Mustard. As a community, we’ve worked hard to spot and get rid of Garlic Mustard. We need to do the same thing for Lesser Celandine. When invasive weeds choke out other native plants, our ecological balance gets out of whack. Losing diversity in your garden doesn’t just affect your plants, it messes with the animals and insects, too. By bringing diversity to your garden, and being a conscientious gardener, you are doing your part to contribute to our long-term ecological balance. This point was driven home in an article in the Evanston Roundtable, which said, “When Lesser Celandine shades out early bloomers and blocks their growth, early pollinators miss out on their usual food sources, which can throw the ecosystem out of balance.” It’s such a bad boy that it even landed on the 2016 “Most Unwanted Invasive Pests” list compiled by the Illinois Cooperative Agriculture Pest Survey Program. Don’t be fooled by invasive plants. Plants like Lesser Celandine are taxing wildlife habitats to the point of no return. As a conscientious gardener, you can do your part by being aware of the invasive plants in your area. Spread the word, but don’t spread the problem. Simply avoid planting them, and instead, find native plants to replace them. In the case of Lesser Celandine, Native Marsh Marigold or Wild Ginger are good alternatives. Be aware that Lesser Celandine is often mistaken for marsh marigold and swamp buttercup, both of which are native plants, so you want to make sure you are getting rid of the correct plants.

What’s the Greenwise solution?

How to deal with Lesser Celandine depends on your lawn or garden and how invasive it is, and it’s always challenging to control and remove. We’ve found the Lesser Celandine starts in the garden beds and if we can control it there, we can help prevent it from spreading to your lawn. Ideally, we would start treating your garden beds from early March through May. For unmaintained garden beds or for garden beds that have been invaded by Lesser Celandine, we recommend our hardscape weed management service to help keep the seeds from spreading. This would need to be a recurring spring service to keep it under control and eventually put an end to it. Lesser Celandine is aggressive and because it grows through both tuber and seed, it’s challenging and needs a long course of action, so it’s definitely a process and not a one-and-done treatment. We’ve also found sheet mulching to be effective in combination with our weed management. Our garden maintenance crew also handle weeding in an effort to remove the leaves, which will then keep the plant from photosynthesizing and from spreading. It is possible to manage a smaller growth by pulling or digging up the plant and the tubers entirely. Don’t leave a bit of tuber behind, or it will explode back into action. And, just know that the process will take persistence and vigilance. Plus, when you dig out Lesser Celandine, you want to be careful that you aren’t harming your other native plants. Need help? Please call us at 847.866.1930.

Where can I find out more about this invasive weed?

Check out this short video from a naturalist at the Rocky River Nature Center in Cleveland or this profile from the USDA Agricultural Library.