The catmints are some of the most harmonious of plants against brick and stone, softening the hardness with their gentle texture and colouring. Of these herbaceous perennials, ‘Six Hills Giant’ is a particularly robust variety, about 30 inches (75 cm) tall, with grey-green aromaticand lavender-blue, labiate that continue all through the summer. It is a fine middle border plant, with the virtue of being self-supporting.
A group of five plants, placed 2 feet (60 cm) apart, would blend with other herbaceous perennials or with shrub roses. A combination that I have particularly admired is its soft blueagainst the apricot clusters of the musk rose ‘Buff Beauty’.
x faassenii, which grows to about 12 inches (30 cm), is smaller in all its parts and looks well drooping down over a wall or across a path. As well as its merits for the front of a border, the plant is a good filler for odd corners.
Nepetas can be clipped after the first blooming, but the second flush of stalks and flowers should be left uncut through the winter to protect the heart of the plant from frost.