It is not neccessary to control lesser celandine in all situations - it can provide colour at a time when the ground tends to look bare and offers valuable nectar and pollen for early emerging pollinators such as queen bumblebees. It also does not tend to swamp or outcompete other plants. Where it is considered a nuisance, control can be difficult.
The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.
There are a number of cultural control methods to try;
- Attempting to dig out the plants often assists their spread as, unless great care is taken, this operation will distribute the tubercles (small tubers). Dig out tubers and young plants before flowering but may need to be repeated over several seasons
- Celandine can be troublesome among spring-flowering bulbs or plants such as primroses. Where bulb borders are heavily infested, it is best to lift the bulbs and desirable plants when dormant and plant them elsewhere for a season while the border is thoroughly cleared of the celandine
- Mulching the surface of the soil with a 10cm (4in) deep layer of organic material may smother lesser celandine, but this method is not always feasible and is unlikely to fully eradicate the weed
- Celandine in lawns is difficult to eradicate, as it is resistant to most lawn herbicides. An application of a selective lawn weedkiller based on MCPA (e.g. Vitax LawnClear 2 or Weedol Lawn Weedkiller) may considerably check growth, but will almost certainly need a repeat treatment the following spring. The first application should be given early in the season (as soon as the leaves are fully developed), followed by a second application three or four weeks later
- Remove all cultivated plants first and then use a glyphosate spray (e.g. Roundup Fast Action, SBM Job done General Purpose Weedkiller or Doff Glyphosate Weedkiller). If plants can't be moved, a ready-to-use spray (e.g Roundup Fast Action Ready-to-Use, SBM Job done General Purpose Weedkiller Ready-to-Use, Doff Advanced Weedkiller Ready-to-Use) or gel formulation (Roundup Gel) can be used with care around garden plants. When treating, branches or shoots of garden plants can be held back, using canes, or by covering or screening while spraying, but make sure the weed foliage has dried before releasing branches or removing the covering
- SBM Job done Path Weedkiller (ready-to-use only) and Weedol Pathclear products containing glyphosate/diflufenican and can be applied once a season to natural surfaces where no plants are to be grown, and can also be applied under and around established woody trees and shrubs. This product kills off existing small green growth and prevents or checks developing growth. Check manufacturer’s recommendations before use to avoid damaging sensitive plants
Inclusion of a weedkiller product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.
Weedkillers for gardeners (Adobe Acrobat pdf document outlining different weedkillers available for gardeners; see sections 1b, 4 and 5)
Chemicals: using a sprayer
Chemicals: using safely and effectively
Chemicals: using spot and broad-scale weedkillers