Posted: 21/04/2014 at 22:45
It's all been said, it is a very difficult weed. I have successfully controlled it with glyphosate but it has taken three years and that has been tackling intact plantings (rather than chopped up pieces that grow erratically) and starting with large horsetails with lots of receptive leaves. Their are lots of wrinkles to enhance absorption of glyphosate as other comments indicate. It is impossible to eliminate if it is growing amongst established herbaceous plants. Under a higher canopy of shrubs it will still take three or more years but at least you can enjoy the shrubs.
On allotments some gardeners just regularly hoe it and think of all those lovely nutrients the horsetail is mining from seven foot down. It will keep coming from the roots but the hoed off tops will not grow!
I wonder if the lawn is mown often enough that you can live with this dreadful weed.