Contact weedkillers will burn and kill the foliage, but will have no effect on the roots, which will continue to grow, produce new leafy growth and spread further.
For best results, spray with a weedkiller based on glyphosate. This is a systemic weedkiller, which is absorbed by the leaves, then moves down to the roots to kill them.
To ensure the weedkiller works effectively:
- Spray the leaves when the ground elder is growing actively; this is mainly from March/April to September/October.
- The larger the leaf area present, the greater the amount of weedkiller that can be absorbed and move down to the roots. So don’t bother spraying when the growth first emerges through the soil – wait until the leaves unfurl and enlarge.
- Use a fine spray to thoroughly coat the leaves in small droplets.
- During the summer, spray in the evening to prevent the spray evaporating and to give maximum time for the spray to be absorbed. In spring or if overnight dew is forecast, spray earlier in the day to allow the spray to dry before dew falls.
- One application of weedkiller is unlikely to kill all the ground elder. You may need to spray once, allow the ground elder to die down, and then spray any regrowth again. Three or more applications a year, over a couple of years, may be needed to completely kill it, depending on how extensive the root system is.
Most contact weedkillers and glyphosate are total weedkillers – that is they will damage or kill any plants whose leaves they are sprayed on. Make sure you keep the spray off wanted plants – including lawns – and, if necessary protect plants by covering with polythene or similar when spraying.
Roundup Gel, which is smeared onto, and sticks to, the weed leaves, may be a better option when trying to treat ground elder growing through or close to wanted plants.
Use weedkillers safely. Always read the label and product information before use.