There are a number of weed control options available to treat nettles. In addition to traditional weedkillers there are now also a range of more natural alternatives.
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. Constant spraying whenever new leaves are produced will weaken and kill it in time.
For best results, spray with a systemic weedkiller. A systemic weedkiller, which is absorbed by the leaves, then moves down to the roots to kill them. “Tough weed” formulations will give better control. Older, woody growth may not absorb the weedkiller as effectively as younger growth. In which case, for well-established clumps of nettles, cut down the plants to ground level and then treat the resulting new growth.
To ensure the weedkiller works effectively:
- Spray the leaves when the nettles are 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. So don’t bother spraying when the growth first emerges through the soil – wait until the leaves grow larger.
- 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 may not completely kill the nettles. You may need to spray once, allow it to die down, and then spray any regrowth again. Three or more applications a year may be needed to completely kill it, depending on how extensive the root system is.
Most contact weedkillers 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.
Gel products, which is dabbed onto, and sticks to, the weed leaves, may be a better option when trying to treat nettles growing close to wanted plants, where drift of the spray would damage them.
In lawns, use a good lawn weedkiller.
Use weedkillers safely. Always read the label and product information before use.