You asked if you could use our product BuckShot to control gorse among a Leyland Cypress hedge, without damaging the hedge. I’m afraid I don’t know. BuckShot contains picloram, and of the many NZ registrations for herbicides containing pictorial there is not a word of advice regarding its effect on cypress hedge plants. Use within a hedge was never envisaged in our own registration because we developed and market the product for spot treatment of woody and broadleaf weeds in pasture. However, based on the kinds of plants that are known to be susceptible to picloram, I reckon that it is very likely to unacceptably damage the Leyland cypress: I can’t think of any reason why this hedge plant would be resistant to picloram. Not what you wanted to hear I know, but it’s not a use that we wished to register for BuckShot, so we have done no relevant experimental work. Nor, as far as I can discover, has anyone else. You could try it on a small area and observe the results, but I’m not optimistic that it would be safe.