(Editor's Note: This article was originally published on March 11, 2007. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
An essential plant in any xeriscape, Penstemons are unsurpassed in attracting hummingbirds to your garden. For beginners, we recommend growing a few of the easier species like Rocky Mountain Beardtongue (Penstemon strictus), Pineleaf Beardtongue (Penstemon pinifolius) and the beautiful Penstemon ‘Elfin Pink’.
Because many Penstemons are adapted to harsh Western habitats, it is important to keep a few cultural considerations in mind when bringing them into our gardens:
- Plant only in well-drained soils; wet clay soils and Penstemon aren’t compatible. Avoid overly enriched soils; too much compost can shorten their life span.
- Plant high, leaving the top of the rootball just above the surrounding soil to avoid burying the crown of the plant.
- Avoid bark, grass clippings or compost as mulch materials. These mulches are detrimental to healthy Beardtongues. They will cause disease in wet, cold weather. It is better to leave them non-mulched or use gravel.
- Allow to re-seed. Penstemon will sometimes live for only 2 or 3 years (e.g., Penstemon palmeri). To keep them going, allow some of the plants to set seed (don’t deadhead them). The volunteer seedlings will be more vigorous and longer lived than the original parent plant.
- Fertilize sparingly. Beardtongues like “tough love” and need only to be fertilized once each year in the fall. Apply a light application of an organic or natural fertilizer. Yum Yum Mix is an excellent fertilizer for Penstemon and other native plants. It has a high trace mineral and phosphorus content while being low in nitrogen.