Penstemons are easy to grow, providing reliable, late summer colour into autumn.
Penstemons are popular plants for mixed borders, adding reliable colour right through to mid-autumn.
Our favourites for this month include Electric Blue, with its compact habit and impressive blue flowers that last from June through to September and Garnet, a taller, reliable variety with dark foliage contrasting wine-red flowers.
Growth is best in a sunny spot with fertile soil and good drainage but they can also tolerate light shade. By removing spent flower spikes, you can prolong your display until the first frosts in autumn.
Penstemons can get woody and leggy if not pruned regularly. Hard prune from mid-April to mid-May, as the old stems can provide shelter to the main crown during winter.
Like most perennials, penstemons look their best when planted in drifts. Pair these plants with other herbaceous perennials such as salvia, perovskia, and nepeta. For a colourful, late summer display, try planting them with aster, rudbeckia, echinacea and crocosmia.
• Remove spent flower spikes to prolong flowering
• Generally disease free, but watch out for frost damage or powdery mildew
• Hard prune in late spring