How to Grow and Care for Foxglove Beardtongue

Foxglove beardtongue, known scientifically as Penstemon digitalis, is a perennial native to North America. Its tubular white flowers appear on strong stems from late spring into summer, attracting a wide range of pollinators, including long-tongued bees, bumblebees, and hummingbirds. This plant has earned a reputation for being a hardy and versatile, long-lived species suitable for many garden designs. It can be massed in perennial borders, used in cut flower gardens, or incorporated into naturalized areas and meadows.

Ideal Planting Conditions

The plant performs best when it receives at least six hours of direct sunlight daily. This level of sun exposure helps ensure vigorous growth and the development of sturdy stems capable of supporting its abundant flowers. While it can tolerate partial shade, this may result in less dense growth and fewer blooms.

This species is highly adaptable to different soil textures, including clay, loam, and even compacted sandy soils. The most important soil characteristic is good drainage, as the plant is susceptible to root rot in overly wet conditions. It grows well in average to poor soil, making heavy amendments or rich compost unnecessary for its success.

When placing plants in the garden, space them approximately 18 to 24 inches apart. This spacing allows for proper air circulation and gives each plant room to reach its mature size. Foxglove beardtongue is reliably hardy in USDA zones 3 through 8, meaning it can withstand winter temperatures in a broad range of climates.

Ongoing Care Requirements

The plant is notably drought-resistant and can handle dry conditions well. Newly installed plants should be watered more frequently for the first couple of weeks to help them establish a strong root system. After this initial period, you should allow the soil to dry out between waterings, as overwatering can cause problems.

Foxglove beardtongue thrives in average or even lean soil and does not require fertilization. Applying fertilizer or planting it in overly rich soil can be detrimental to the plant’s structure. Forgoing fertilizer is a simple way to maintain the plant’s natural, sturdy form.

Pruning and Maintenance

After the initial wave of flowers fades in early summer, you can deadhead the spent blooms by cutting the flower stalks back. This practice can encourage the plant to produce a second, smaller flush of flowers later in the season. Removing the old flowers also prevents the plant from setting seed, which is a useful method for controlling its spread if you wish to prevent it from self-sowing in the garden.

As the growing season concludes, there are two main approaches to cutting the plant back. For a tidier winter garden, you can cut the stalks down to the basal foliage in late fall. Alternatively, the stalks and their attractive reddish seed pods can be left standing through the winter. This provides visual interest in the landscape and offers a food source for birds. If you choose this option, you can then cut the old growth back in early spring to make way for new shoots.

Common Problems and Solutions

Foxglove beardtongue is resilient and is not troubled by many pests or diseases. The most common issue gardeners encounter is root rot, which is almost always a direct result of poor soil drainage. Ensuring the plant is in a location with well-aerated soil that does not remain waterlogged is the most effective preventative measure. Good air circulation also helps prevent the possibility of fungal issues.

Another frequent concern is floppy or weak stems. This problem is not caused by a pest but by environmental conditions. The primary causes of floppy stems are too much shade or soil that is overly rich and fertile. If you notice your plant’s stems are weak, the solution is to assess its location and soil rather than providing physical stakes. The plant will have its strongest, most upright growth in full sun and soil that is not heavily amended.