Perfect penstemons

Easy-going and with a long flowering season right up until the first frosts, penstemons are excellent border perennials available in a range of colours.

- Anne Swithinbank

FOR their easy-going nature and cute flower buds opening to tubular flowers in jewel-like colours, penstemons are a top favourite in my garden. I know that once established they will be drought-tolerant, thrive with no extra feeding, won’t need staking and are never nibbled by slugs, snails or rabbits.

The 250 penstemon species are mostly from North and Central America and are sometimes called beardtongues, as some have a hairy sterile stamen protruding from each flower. Plant breeders have raised many named cultivars that are perfect for borders and containers.

Long season of flowering

Earlier breeding concentrated on large-flowered but rather tender plants prized for labor-intensive Victorian bedding schemes. Older plants would be scrapped in autumn and replaced the following year by young stock raised from cuttings the previous summer. Modern breeding has concentrated on hardier, natural-looking cultivars with a long season of flowering. Most are under 3ft (1m) tall, semi-evergreen and perennial with a slightly woody base.

Most penstemons flower from midsummer to autumn. Old stems are left in place as protective cover for winter, and only when new shoots are growing from the base in spring are they pruned away. Now is the time to order young plants for setting out in late spring.

Penstemons are long-lived

Given a sunny position and well-drained soil, penstemons are long-lived and hold their own in mixed borders. In my garden they occupy a raised bed with a rosemary and shrubby salvias. Further down the garden and in heavy soil, a group of ‘Andenken an Friedrich Hahn’ has been flowering every summer for seven years alongside rambling rose ‘Phyllis Bide’ and a young variegated holly.