Fill modules with the compost mix for lemon verbena and firm in. Dig up some Corsican mint, or remove side shoots from a pot-grown plant with the roots attached. Cut off excess roots or top growth.
Gently push the roots into a hole in the compost. Back-fill and firm so the top growth is on the surface. Water well and place in a cold greenhouse, or on a cool windowsill. Don't let the compost dry out.