Showy penstemon

Penstemon spectabilis

Description

The Showy penstemon is one of the outstanding native perennials of Southern California where it commonly grows in sage scrub and chaparral plant communities. It is a tall species that produces numerous 3-5 ft. tall stems that become covered with rich purple-blue flowers in mid to late spring.

Showy penstemon is naturally suited to native landscape plantings in the Inland Empire in combination with the Coast live oak and the Desert willow. It grow best on well drained soils, in full sun and with low amounts of supplemental water during summer. It combines well with other scrub and desert perennials and around boulders, on banks and for seasonal accent value.

Because it usually gets cut back hard after flowers have dried out and seeds have been set, it is best used in gaps among low shrubs or bunch grasses where it will largely blend into the landscape when not in bloom, but then steal the show in the spring when its long flower stocks reach high.

This is a favorite to mix amongst a large planting of deer grass for a show of spring color in a meadowy situation.

Plant Type: Perennial, Native
Foliage Character: Evergreen
Habit: Upright, Clumping
Growth Rate: Fast
Foliage Color: Medium green
Flower Color: Purple, Blue
Flower Season: Spring
Soil Adaptations: Well-draining soil
Exposure Adaptations: Heat, Drought, All day sun
Function: Wildlife value, Hummingbird plant, Attracts butterflies, Flowering accent plant, California native, Borders
Height: 1.5 ft. (3 ft. while flowering) – 2 ft. (5 ft. while flowering)
Width: 2 ft. – 4 ft.

Watering Schedule: Low 1

For most situations, we recommend watering deeply every 3-4 weeks after establishment.

Learn how to apply this watering schedule to your landscape on our How to water waterwise and California native plants page.

Important Notes

These are general guidelines. Always observe and adjust as necessary for your landscape.
If it rains over 1” you will likely not need to water for at least another 3-4 weeks. Before watering again, check the soil. It should be significantly dry at least 4” below the soil surface before watering.
If you have a “smart timer” or weather sensitive irrigation controller, it is best not to use the automatic weather adjusting features for plants in this category. While very useful for watering higher water demanding plants, those in this category have natural drought adaptations which mean they do not need to be watered more in warm weather. Using the weather adjusting features will result in either overwatering in summer or underwatering in fall and spring.
It is important to group plants with the same water needs together in the landscape to avoid needing to over or under water plants when running your irrigation system.

Remove dead flower stalks after flowering in late Spring or Summer (1). Consider leaving some stocks on established plants to develop seed for wildlife food and for “volunteers” to develop in the landscape (S) Showy penstemon is a very tough locally native plant, but may look quite dormant in summer if left dry. If you think the plant is dead, and are not sure, cut back some and wait until cooler weather to see if it begins to grow again. If all the stems are completely dry and brittle though, it is likely dead. Individual plants often only live for a few years in gardens, so it is best used as an accent plant. However, if the seed is left to develop and dry out before cutting back, showy penstemon will often lightly “self seed” in the garden, so you will still have this species present in your yard. Further encourage this by leaving your trimmings of showy penstemon in the yard to become part of the natural mulch layer. You can leave the stocks long or cut them up. The semi-hollow stems might also eventually be used as nesting sites for some of the native, non-stinging, bees that lay their eggs in hollow stems (S). References