Verbena rigida (Rigid Verbena, Sandpaper Verbena or Tuberous Vervain)
This is a colorful groundcover plant that blooms in rich purple for a long flowering season. The leaves are coarse and tough with a sandy texture and the plant creeps and crawls with underground runners. Flowers are clustered in groups and grow from six to eighteen inches high. The color can be a vibrant violet. The Verbena rigida likes full sun and well-drained, lean soil, but it isn’t fussy about soil type. It thrives in high heat and is frost tolerant to 15 degrees Fahrenheit. This is an ideal plant to cover hills, slopes and open expanses. It has an informal habit of growth that will make it attractive in a natural garden. It can become invasive where happy and rambles too much to work well in a formal, controlled landscape design. In the right location, the Verbena rigida is an excellent choice for a water-wise garden, although it won’t mind if it gets regular water either.
Be warned that sometimes this Verbena takes a while to become established. Wait a year or two before replanting. It can suddenly take with extreme enthusiasm. It can also establish itself in places you never intended. This is another plant that spreads by both seed and underground runners. It’s ability to adapt to dry, stony soil allows it to spread easily once happy. If you have good soil and a fair amount of water, you may be wise to choose another variety of Verbena that is less invasive. But for tough, hot, dry spaces, it’s a colorful plant that is hard to beat.