Horehound ( Marrubium rotundifolium ) ‘Silver Edged,’ also known as Silverheels Horehound, is a low-growing, drought-tolerant groundcover that I highly recommend for difficult, dry spots in the garden. It thrives in hot, dry conditions and poor soil, and its soft, silvery foliage has an almost felt-like texture. In our garden, plants that prefer dry conditions are actually a challenge. I’ve killed numerous agaves and other xeric-type plants. I’m sure it’s because we water regularly, and I always amend the soil with compost and manure. However, the planting strip along the roadside doesn’t get as much water as other parts of the garden. I would guess that it is also the hottest area of the garden. Even though it is north-facing, the area gets quite a bit of sun, especially during the height of summer. I’ve tried to plant mostly species along this stretch that appreciate these conditions, although I’m not always successful, and inappropriate plants keep sneaking in. When I do water this ...