Moss Verbena may end up being your favorite groundcover. It grows between 6 to 12 inches tall, but has a spreading capability of up to 5 feet. It's easy to grow, is drought and heat tolerant, attracts butterflies and comes in blue, purple and white flowers.
Nasturtiums are so versatile. They grow easily from seed sown directly in your garden's poorest soil and blooms all season until frost and are never greedy about food or fertilizer. Nasturtiums are available in either spreading or climbing types.
Potato bush blue (Solanum rantonnetii) s a deciduous shrub forming purple-blue flowers throughout the summer, followed by red decorative fruit in autumn which is popular with the birds. Grow in moist, well-drained soil in full sun, against a sunny wall.