How to Get Rid of Lesser Celandine

Treat it while it is green, in early spring. A small patch can be dug if you remove every tuber; anything larger needs a herbicide, and mowing makes the problem worse. The reason is the plant’s calendar: lesser celandine disappears underground by early summer, and once it is gone there is nothing left to treat.

When to treat lesser celandine

Lesser celandine is a spring ephemeral. It comes up before the trees leaf out, flowers, sets seed and bulbils, and then dies back. Penn State Extension says the leaves and flowers are generally gone by late May in Pennsylvania. The Wisconsin DNR says entire plants can be dead by June. By then the tubers are underground and waiting for next spring.

That leaves a short working season.

Timing moves with latitude. The University of Maryland Extension says growth can begin as early as February once temperatures climb above 40°F. The Wisconsin DNR puts flowering at March and April. In all three states the rule is the same: treat early, while the plant is still green.

Dig only what you can finish in an afternoon

The sources do not fully agree here, and the disagreement is worth understanding.

Penn State Extension says digging is not recommended. Its reasons are practical: it is very difficult to get all the tubers, and doing it properly means removing excessive amounts of soil. The University of Maryland Extension and the Wisconsin DNR both say small colonies can be dug if you remove all the roots, tubers and bulbils. Wisconsin adds that hand-digging is difficult in larger populations because of the soil disturbance and the number of small tubers.

Those positions are closer than they look. Everyone agrees that a missed tuber means the patch comes back. Digging is a reasonable choice when the patch is small, the soil is soft, and you can sift through what you lift. It is a bad choice for a carpet that covers a lawn.

If you dig:

• Work when the soil is moist, so the tubers come out whole.
• Bag every piece. Penn State Extension says all plant parts must be sealed in a bag for burning or trash.
• Do not compost the material. The Connecticut invasive plant disposal guidelines list fig buttercup, the plant’s other common name, as a species that should never be composted because its tubers survive.
• Check the spot again next spring. Tubers left behind will send up new leaves.

For the wider non-chemical picture, including why vinegar and boiling water do not reach the tubers, see how to get rid of invasive plants without chemicals.

Bulbils are the other reason to bag everything. Penn State Extension says bulblets that drop from the stems can produce new plants, and they move on boots, tools, water and soil.

Do not mow

Penn State Extension is direct: do not mow lesser celandine. Mowing can spread the plant, and it also reduces how much herbicide the leaves take in. The University of Maryland Extension adds that mowing has little effect on the tubers, which is the part that matters.

If the infestation is in a lawn, mowing may be unavoidable while you plan treatment. Treat that as a delay, not a control method.

What the extension programs name for herbicide

The active ingredients below are the ones named by Penn State Extension, the University of Maryland Extension and the Wisconsin DNR. This page does not give rates. Product strengths differ, and the label for the product in your hand is the only rate that applies.

• Glyphosate. All three sources name it, and Penn State Extension calls it the most effective active ingredient for lesser celandine. It is systemic, meaning it moves from the leaves to the tubers. It is also non-selective, so it will injure or kill other green plants it contacts.
• Triclopyr. Penn State Extension names a triclopyr-ester product for lawns, where it can reduce celandine without killing turfgrass. The University of Maryland Extension also lists triclopyr for turf.
• 2,4-D, dicamba and MCPA. Penn State Extension reports that these can give some control when at least two are combined. The University of Maryland Extension lists dicamba for turf.
• Metsulfuron-methyl. Penn State Extension names it as another option for lawns, with the caveat that it works more slowly than glyphosate.
• Sulfentrazone. The University of Maryland Extension lists it for turf.

Three conditions come with the treatment:

• Near water, use an aquatic-labeled product. Penn State Extension says to use only aquatic-labeled herbicides in or near water and to avoid spraying the water itself. The University of Maryland Extension says the same for wet areas.
• Apply when the air is at least 40°F. That is Penn State Extension’s minimum.
• Treat before native plants and amphibians are active. The Wisconsin DNR makes this point for spring treatments.

Follow the product label; the label is the law. If the label and this page disagree, the label wins.

Expect to repeat it

One treatment will not clear a stand. Penn State Extension says control efforts need to be repeated once a year for at least a few years, probably more for large infestations, and that the site should be watched for several years after the celandine seems gone. The University of Maryland Extension describes the same pattern: repeated annual applications, then monitoring.

Plan the follow-up before you start. A single spring pass buys a thinner patch, not a finished job.

What to plant after

Lesser celandine wins by covering the ground early. Penn State Extension notes that desirable plants will grow back in time or can be planted after the celandine is controlled, and it suggests reseeding spots where grass was killed. The University of Maryland Extension points out that it gets a head start on native spring ephemerals such as mayapple and Dutchman’s breeches, which are still mostly dormant when it is already growing.

Do not leave bare soil. It invites the seed bank and the next invader.

In wet ground, check the native look-alike first. Marsh marigold is native and looks similar, and it belongs in wet sites, not lawns. See lesser celandine vs marsh marigold before you dig or spray a yellow-flowered patch beside a stream.

Related WildScope pages

• Lesser celandine species profile for identification and look-alikes.
• Lesser celandine vs marsh marigold for the native that should be left alone.
• How to dispose of invasive plants for bagging tubers and bulbils.
• When to treat invasive plants for how this window fits the rest of the year.
• Removal guides for other species.