Introduction:
Creeping buttercup (Ranunculus repens) Weed.
Creeping buttercup is a low-growing, perennial species of buttercup originally from Europe and now found throughout North America and many other parts of the world. This competitive plant spreads by stolons and forms thick carpets on wet, poorly drained soils everywhere from farms to city gardens to natural wetlands.
Impacts:
Creeping buttercup patch - click for larger imageCreeping buttercup’s competitive growth crowds out other plants, especially in wet soils. One plant can spread over a 40 square foot area in a year. Creeping buttercup also depletes potassium in the soil and so can have a detrimental effect on surrounding plants. Because creeping buttercup can tolerate heavy, wet soils, it can be a particularly bad problem on well-watered lawns, wet meadows and poorly drained pastures. In addition to invading wet grassy areas, creeping buttercup is reported as a weed of 11 crops in 40 countries.
Fresh buttercup plants are toxic to grazing animals, who can suffer from salivation, skin irritation, blisters, abdominal distress, inflammation, and diarrhea. Fortunately, buttercup has a strong, bitter taste so animals generally try to avoid it if more palatable forage is available. Also, the toxin protoanemonin is not very stable and loses its potency when dry, so buttercup is not generally toxic in hay. Unfortunately, livestock occasionally develop a taste for buttercup and consume fatal quantities. It is safest to keep populations of buttercup under control on grazed pastures and offer plenty of healthy forage.
Control:
Prevention and cultural control:
- In lawns and pastures, promote healthy grass by overseeding, fertilizing as needed, and not over-grazing. Adding lime can improve grass health and keep buttercup from re-establishing. However, lime won’t control buttercup that is already well-established.
- It also helps to improve soil drainage. Reduce compaction by aerating and avoid trampling when soils are wet.
- Clean mowers and other equipment to avoid spreading buttercup seeds to un-infested areas.
Creeping buttercup (Ranunculus repens) Distribution in North America shown in green.
Manual:
- Dig out with a sharp trowel or fork-type tool, removing all of the runners, roots and growing points. Digging is most effective from fall to spring while the soil is moist and roots won’t break off as much.
- Cultivating or incomplete digging may increase the buttercup population because it can sprout from nodes along stem and root fragments.
- Disturbance of the soil can increase seed germination. Seeds stay viable for 20 years or more and the number of seeds in infested soils can be immense compared to the number of plants present, especially in long-term pastures and woodland ecosystems.
Mechanical:
- Creeping buttercup’s growing point is at soil level, so plants resist mowing and quickly re-sprout when cut.
- Regular cultivation can kill the buttercup but plants buried by cultivation can grow back up through deep soil and re-establish themselves and long-lived seeds in the soil can germinate and re-infest the area once cultivation ceases.
Close up of the Creeping buttercup (Ranunculus repens) Weed.
Chemical:
- Herbicides can be used if allowed and appropriate for the site and land use. Follow all label directions to ensure safe and effective use.
- Glyphosate (e.g. Roundup, Aquamaster) can be applied to actively growing plants before they seed. Keep spray off of grass and other plants. Re-seed or re-plant bare areas after removing buttercup to keep it from re-infesting the area.
- Broadleaf herbicides can be applied over grassy areas infested with creeping buttercup to selectively kill the buttercup and not the grass. Products containing the active ingredient MCPA are most effective on buttercup. Metsulfuron (Escort, Ally) is also effective but can harm some grasses. Follow label directions on timing and rates.
- It will probably take at least two or three applications to eradicate creeping buttercup because of the seed bank and because some mature plants will generally recover.
- Monitor the treated area for re-growth and pull up any new seedlings before they establish runners.
Make sure to have a long-term plan to ensure success, protect native and beneficial species while doing the control, and start in the least infested areas first and then move into the more heavily infested areas.
Sourced From: www.kingcounty.gov › Noxious weeds › Weed identification photos
