Under Schedule 9 of the Wildlife and Countryside Act (1985 and amendments) it is an offence to deliberately or accidentally introduce this plant into the wild. Make certain when harvesting, to use suitable containers that do not allow any part of the plant to accidentally fall out when transporting back home. And dispose of any unused material safely (not your own compost bin, or green bin, instead use black bin). – Mark Duffell from Arvensis Ecology