Thanks for asking. We don't use weed barrier. Ultimately most brands and products fail in the Northwest. I carefully discuss this with the clients and then plant it heavily in order to get cover as soon as possible. In this case the client wanted this specific ground cover. It is beautiful as I agree. I generally use Elfin Thyme it is a bit tougher and the deer don't seem to like it. The client did tell me this was too much work for her hands and knees. M