The flowers of this native penstemon are almost an electric blue, and very profuse. It blooms in spring, and creates quite a show in the garden when planted with California poppies and other spring wildflowers. Plant this small perennial close to the front of the border. The flowers attract hummingbirds and butterflies.
Penstemon heterophyllus needs full sun. It can tolerate average garden water, and most soils as long as the drainage is good. It grows naturally in Chaparral and forest openings in the Coast Ranges, and at lower elevations in the Sierra.
While traveling the forest roads through Mendocino National Forest, we came upon a recent road cut where the steep slopes on either side had been colonized by Foothill Penstemon -- It was a memorable and breath-taking spectacle!
Instructions for Growing Penstemon from Seed
The seed is small but needs no pre-germination treatment when sown outside in early fall. Prepare your seed-starting mixture, tamping it down solidly into the pot; rough the surface just a bit and sprinkle the seed on the surface. Then cover it with a thin layer of perlite or vermiculite, and tamp that down over the seed.
Germination is somewhat slow; it can be 6 to 8 weeks before the first seedlings appear. I usually use plastic nursery pots or flats to start seeds, but they keep the soil really moist and sometimes also soggy at the bottom; this may be detrimental to the early growth of the seedlings. I’ve been using a clay "bulb" pot (large in diameter, but shallow) to germinate and grow on the Penstemon seedlings, and getting better results.
I set my seed pot outside in a somewhat shady and protected place, either watering only once when I set it all up and then letting the rainy season take over, or I’ll put the pot on my seedling bench where I have systems set for a light watering once a day. Within two months or so after germination, the seedlings will be large enough to transplant to individual pots. Note the nice reddish color on the healthy young stems.