How quickly will they spread?
We’ve rated the plants on this site by their approximate rate of spread (slow, medium, fast) and also given the approximate range of spread in both inches and centimeters. If you plant them about the same distance apart as they will grow in width, the plants should eventually join together to form a solid patch on average after about two growing seasons. Obviously, the faster the rate of spread, the more quickly this will happen. If you choose a slow-spreading plant and want faster results, just place them more closely together at planting time.
