If you want a nice garden sandyRoe by all means cut down your nettles, and plant other pretty plants that insects like just as well. I planted out rows of Marigolds, Verbena, Busy Lizzie and Dianthus to find that the Marigolds were stripped of their leaves in no time, all the other plants were OK, then I found too late, several large slugs 8" long and snails were the culprits. We have just started on our garden since moving in. The grass was long, when it was cut we found a resident frog sitting in the middle of the lush lawn, what to do with him? We tidied back the overgrown Iris, crocosmia and phlox to find another frog emerging from the soil. So I've left some oasis for them around the borders. The slugs and snails I've kicked out to the garden waste bin.