ASK CARIANNE -Native penstemons re-seed themselves in landscapes, can I control where they grow?
Posted Jun 15, 2021
Caroline asks: I heard that our native penstemons re-seed themselves in landscapes, but I want to have a little more control over where they grow. What should I do?
Here we are in the middle of a mid-June heat wave. If you had penstemon flowers this spring, the seedpods are probably good and dry right now…I like to cut the stalks and then carefully turn them upside down in a 5-gal bucket, shaking the stalk against the side of the bucket to knock all of the seeds loose. Wah-la! Clean seeds that you can share with your friends or sprinkle in areas of your yard where you’d like some more penstemons. I like to hold onto my seeds, keeping them stored in paper envelopes or uncovered glass jars until I am ready to scatter them during the monsoon or fall. I don’t let those stalks go to waste, either – they make great mulch under trees or shrubs.
According to SEINet, there are 15 species of penstemon within 30 km of Tucson.
Parry’s penstemon (Penstemon parryi) is most commonly used in Tucson landscapes, with its sprays of bright pink flowers in March – May. Once you’ve mastered this one in your garden, I recommend branching out – others that I have had great success with in the low desert are
red-flowered firecracker penstemon (P. eatonii),
pink-flowered desert penstemon (P. psuedospectabilis),
and superb penstemon (P, superbus). Increasing your penstemon diversity will create overlapping bloom periods – with these four species, you could have penstemons of different varieties blooming from February to July! Hummingbirds and many other pollinators will thank you.