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Invasive Plant: Lesser Celandine

Information
Photo shows a dense mat of yellow-flowered plants that are an invasive species.
Be cautious of lesser celandine at plant swaps or when sharing plants with friends and neighbors. It was once sold as an ornamental plant and has become common throughout Portland. Lesser celandine is known for blanketing yards and natural areas.
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 At a Glance

  • Scientific name:Ficaria verna (previously Ranunculus ficaria)
  • Annual, perennial, or biennial? Perennial
  • Conditions it likes best: Lesser celandine likes shade and moist soil, but does well in sunny, drier places, too.
  • How it spreads: Through seeds, bulblets, tubers, and tuber fragments. This flexibility makes especially difficult to control. .
  • How it causes damage: Pushes out other plants by taking space and nutrients before other plants emerge in the spring. Then, in April and May, it dies back to underground roots and tubers, leaving bare soil during spring rains. This creates erosion as soil washes into streams, harming fish and insects.
  • Best time and way to manage: Late winter/early spring is the best time to remove manually by pulling and digging bulbs or with herbicide. Some plants now emerge as early as December, with flowers by late January.  
  • Oregon Department of Agriculture noxious weed rank: B
  • Report patches of this plant? No. If it’s on your property, find information below on how and when to remove it.

How to Identify Lesser Celandine

Photo shows 9-petaled yellow star-shaped flower surrounded by green heart-shaped leaves
Lesser celandine blooms much earlier than most flowers – from February to mid-March. 

Winter – Rosette. Lesser celandine can emerge as early as December but normally in January. The plant has a rosette (flat circle) of dark green, shiny leaves that are round or heart-shaped.

Plants will flower from February to mid-March. The bright yellow flowers bloom much earlier than most other flowers and are 1-2 inches across. Flowers have between six and 26 petals, with each flower on its own thin stem. Pale bulblets show up on the stems above-ground, but not until flowers start falling off.   

Spring. After flowering, the stems and leaves die back in April and May. Lesser celandine spreads by making a lot of tubers and bulblets. Each is ready to become a new plant wherever spring rains wash them to.

Summer-Fall. No stems or leaves are visible, but your boots can carry seeds in the mud.

How and When to Remove Lesser Celandine

Lesser celandine is very difficult to control, but it can be managed with regular attention over several years.

  • Manual. Digging up lesser celandine is time-consuming and requires careful attention to detail and regular follow-up. Digging or handpulling is only recommended for small patches. Plants, pieces of plants, and the dirt around them should go in the trash, not in compost or yard debris bins. Note: The City does not dispose of this dirt for property owners so have a plan before digging.
  • Herbicide. February and March treatments work best but must be done in good weather. On patches of more than a few plants, herbicides can be used along with the manual methods described above. More details are available from the 4-County Cooperative Weed Management Area.
  • Check. Check the site for new plants at least once a year, and especially for the first 2-3 years after removal.
  • Replant. After a year or two of managing this plant, consider planting native or less aggressive non-native plants. 

Prevention is Best Practice

Clean your boots, pets, and maybe even your tires when you finish a hike or trail ride in Pacific Northwest natural areas, or if you have invasive plants on your own property. Cleaning boots and pets keeps invasive plants from spreading to new places. Be careful when trading plants with neighbors and fellow gardeners to make sure you’re not trading this or any other plant of concern.

Be Aware of Look-alikes

There are two lesser celandine look-alikes.

Photo shows the back of a 9-petaled yellow flower with 3 sepal leaves at the base.
To distinguish lesser celandine from Marsh marigold, look for three light-green sepals behind its petals.
  • Marsh marigold (Caltha palustris) has often been confused with lesser celandine, even though marsh marigold is not native to Portland. One difference is lesser celandine has three light green “petals” under the yellow flower petals. Marsh marigold does not. Also, if it is growing with a lot of other “marsh marigold”  plants, and especially if it is growing like a carpet, it’s not marsh marigold. Be careful and ask questions if someone offers marsh marigold for sale or trade.  
  • White marsh marigold (Caltha leptosepala) might look like lesser celandine before flowers emerge, but its white flowers make it obvious that it is not lesser celandine.

Properly Dispose of Invasive Plants

To prevent spreading invasive plants:

  • Never place plants or seeds in your compost or yard debris.
  • Never throw pulled plants on the ground or into the street or sidewalk.
  • Put all pulled plants, bulbs, or seeds into a plastic bag and put the bag in the trash.
  • Wash all garden tools and gloves.

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