by Bronwynne Bailey
Penstemon is a native plant which acts like a magnet for hummingbirds, bees, and butterflies. The red and mauve varieties shown are the best choices to attract hummingbirds. There are more than 260 different species. This provides you with a large variety of bloom times and heights for your garden. Their flowers, which come in a multitude of colors including red, pink, purple, blue, and white, are tubular shaped with a hairy stamen protruding from the flower. This gives the plant its common name- beardtongue. You can expect the heavily scented flowers from May through July. Penstemon is a perennial plant, living more than two years, but benefits from self-seeding to produce new plants. They are easy to grow and will naturalize over an area when allowed to reseed.
Soil Preferences
Well-draining soil is essential for penstemons. Avoid using peat moss or manure when planting, mushroom compost is preferred. It is best grown in slightly alkaline soils. Be sure to firm the soil around the plant to anchor it.
Planting Depth & Spacing
Plant your penstemon based on species directions. Most prefer full sun but protection from the afternoon sun is beneficial. Some eastern species prefer dappled shade so be sure to learn the light specifications for your type.
Watering
Though listed as a drought tolerant plant, different species of penstemon require different amounts of water. Generally, they need less water than roses or annuals but will require supplemental watering during dry spells. The base of the plant needs to stay dry so place mulch at least an inch from the plant. Pine straw or shredded bark are excellent options for mulching.
Fertilizing
Applying slow-release fertilizer in the spring and after the first flush of blooms is beneficial. Over watering or applying excessive fertilizer can produce floppy stems.
Pruning
Deadheading or light pruning will promote continued flowering. Allowing the plant to self-seed after July will ensure continued plant production.
Propagation
You can propagate through cuttings or seeds. Propagating a cutting in water is an easy way to share your plant. Cut a stem with at least one or two nodes (where the leaves attach to the stem.) gently remove leaves that will be below the water. Apply rooting hormone to increase root development. Place the stem in a clear container with three to five inches of tepid water and change water every three days to reduce bacterial contamination. Be sure the nodes are below water level. Covering the container in a clear plastic bag will reduce rooting time but ensure the bag does not touch the cutting. Once roots develop you can transplant. Be patient as roots may take up to a month or two depending on the species.
For more information, see at the American Penstemon Society webpage. Their annual meeting is in Burley, Idaho June 13-16, 2025. Their recommended reference book is Growing Penstemons: Species, Cultivars and Hybrids. They also provide sources for purchasing the plants and members participate in an annual seed swap.
