Posted: 26/09/2014 at 15:56
The organic way is just to keep pulling them with as much root as possible whenever they appear. They will eventually weaken and be less invasive and easier to deal with. One consolation is that they indicate your soil is fertile and not too heavy and, if you dry them out first, they will make an excellent addition to you compost heap as they are full of nitrogen which promotes leaf growth. You can also soak fresh nettles in buckets of water (covered for the smell) for a few weeks and then dilute the resulting brew 1 part to 10 of water and use it as a liquid feed.
The non organic way is to spray with glyphosate as this kills the plants down to the roots. However with nettles and creeping buttercup and thistles and couch grass you will need repeated applications before they surrender. Glyphsate is not selective so protect any plant you wish to keep before you spray the nettles.