Transplants must be grown without synthetic fertilizers, wetting agents, or pesticides, and with seeds that meet CNG standards. When purchasing transplants, sometimes it can be difficult to tell how transplants were grown. The best ways to ensure that transplants meet CNG requirements is growing them yourself if you are able, or communicating directly with the transplant grower about their practices. For perennials that were started conventionally, they can be considered fully CNG after 12 months under CNG management.