When Should You Cut Back Penstemon?

Penstemon, commonly known as beardtongue, is a genus of herbaceous perennials that bloom in a wide range of colors, adding charm and beauty to gardens. To maintain their health and encourage continuous blooming, proper pruning is crucial. This article will guide you through the best time and techniques for cutting back penstemon.

When to Cut Back Penstemon

The ideal time to cut back penstemon depends on the climate and the specific species. However, there are general guidelines to follow:

In spring (after flowering): For many species, such as Penstemon digitalis and P. heterophyllus, the best time to cut back is after they finish blooming in spring or early summer. This encourages new growth and prevents the plant from becoming leggy.
In late summer or fall: Some species, such as Penstemon barbatus and P. grandiflorus, benefit from a second pruning in late summer or fall. This removes old and faded flower stems, promoting bushier growth and more blooms the following season.

How to Cut Back Penstemon

Follow these steps for proper cutting back techniques:

Use sharp, clean shears to avoid tearing the plant tissue.
Cut back the stems by about one-third to half their length, just above a set of healthy leaves.
Remove any dead, diseased, or damaged stems entirely.
Deadhead spent blooms as they appear to prevent the plant from putting energy into forming seeds.