If you're looking for plants which have a good level of drought resistance, you've hit the nail on the head with Nepeta, commonly known as catmint or catnip. Once settled in, these resilient hardy perennials won't require you to be watering them constantly during hot spells as they prefer their soil to be more on the dry side. Flowering in pretty mauve and white shades with silvery-grey foliage, Nepeta can create a gorgeously hazy pastel effect and also have a pleasant minty fragrance!