Zone: 3 to 8
Soil: Sand to loam
Light: Full sun to part sun
Bloom colour: White, pink and red
Bloom period: June to July
Height: 24 to 36 inches
Moisture: Dry to medium
Attracts: Bumblebees and hummingbirds
Notes: There are hundreds of Penstemons found in North America, but only three species are native to Ontario. The two most commonly available species are Penstemon digitalis and Penstemon hirsutus.
The deep corolla of these plants makes them suited to pollination by long-tongued bees and hummingbirds. Penstemons may sometimes be referred to as beardtongue due to an infertile stamen that protrudes from the flower and which can be hairy. In Penstemon hirsutus, the function of the staminode is to make a bee brush the stigma and deposit pollen from another plant before collecting any new pollen. This encourages cross-fertilisation. You may notice that Penstemon digitalis does not have a "beard". Its staminode is shorter and terminates inside the flower.
Penstemon hirsutus, blooming in late spring, is one of the earlier flowering perennials that provides much needed food for queen bees. Most of the leaves are basal and it grows less than 2 feet high. While Penstemon digitalis seems to be more available in nurseries, Penstemon hirsutus with its dense cluster of flowers is a worthy addition to a flower garden. This plant really needs full sun and dry well drained soil. In part sun, it is unlikely to thrive and will stop flowering. Out of the three plants mentioned here, Penstemon hirsutus is my favourite because it works very well as an edging plant en masse and it blooms for longer.
Penstemon digitalis is a lot more versatile and will grow in a variety of conditions except full shade. It is an easy plant to grow in a garden. It is taller than Penstemon hirsutus and the flowers are borne further apart. It flowers in early summer and combines well with downy woodmint and yellow coneflower as their blooming times overlap. A decent sized patch of this Penstemon digitalis will definitely attract the attention of hummingbirds. Such is not the case for the other two species mentioned here. Penstemon grandiflorus may also attract hummingbirds. It is a near native and it can be grown with some patience in Ontario.
Penstemon gracilis is really a western species with a range that extends into Ontario. It is the smallest of the three species here. It is similar to Penstemon hirsutus and grows in similar conditions but it is a bit daintier and blooms a little later.
Species in Ontario include:
Penstemon digitalis
Penstemon gracilis
Penstemon hirsutus |
