Penstemon cardinalis subsp. regalis



Habitat: sun or part shade


Soil: gritty, well drained


Height: 70 cm


Flowering: late spring to mid summer


Width: 25 cm



This large genus from (almost entirely western) North America is said by some to rival Primula, Gentiana and Saxifraga as a prime genus for the rock garden. We don't rate it quite that highly, but it includes many splendid plants, with the virtue of flowering later than most inhabitants of the rock garden. They range from low mats and cushions from high mountains to tall plants used in herbaceous border, and include both shrubby and herbaceous species, although most are evergreen. The flowers are 'foxglove' like, usually in spikes or arranged in whorls, technically called verticillasters. Virtually all are from rocky places, and require very well drained, gritty soil, with maximum sunshine. Some need protection from excessive winter wet, but those we list are generally easy plants for outdoor cultivation. The rock garden species are inclined to die back after some years, so it is wise to propagate one or two replacements by taking cuttings or separating pieces of the mat.

Penstemon cardinalis subsp. regalis has flowering spikes lined with bright red, tubular flowers, mostly forming on one side of the stem. This subspecies, which comes from New Mexico, has thicker leaves than the usual form, and also differs in the size of the calyx.
1 litre pot £6.00

Penstemon - some other suggestions
penstemon_azureus_azureus_nns05_527.jpg Penstemon azureus has deep purple-blue flowers.
invisible.gif Penstemon campanulatus is a showy species, with flowers that are in the purplish blue to violet range, with red also said to be a possibilty. It comes from Mexico, and is said to be marginally hardy in the UK. That makes us a bit suspicious. Ours (which came originally from seed from the Alpine Garden Society) have been perfectly hardy, and are rather shorter and bluer than we would expect. But still, they are very beautiful.
invisible.gif Penstemon confertus is the only Penstemon species with yellow flowers, which are a pale lemon yellow, and borne in dense spikes. It comes from cool, damp places by woods or streams in the mountains of western North America, and is easy to grow.
invisible.gif Penstemon eatonii is one of the species with brilliant scarlet flowers, and is perfectly hardy in the UK, so long as it does not get too wet. The flowers are long, tubular, spaced along the flower stems, over thick, dark green leaves.
penstemon_euglaucus.jpg Penstemon euglaucus makes mats of waxy, bluish foliage, in basal tufts, providing a foil to the numerous spikes of flowers, which in this collection are dark blue, with red-violet tubes. This is a particularly beautiful species, which is not too difficult to grow in Britain. This collection comes from Mount Hood in Oregon, a fine volcano visible from much of the northern part of the state.
penstemon_garnet.jpg Penstemon 'Garnet' is a herbaceous perennial with spikes packed with flowers, in this case red, very slightly pinkish, so not over-exuberant.
invisible.gif Penstemon hirsutus var. pygmaeus is an easy and rewarding variety, much smaller than other forms of Penstemon hirsutus. It is unusual in that the leaves are a good purple colour during the winter, but the new ones in summer are more green, although still tinger with purple. The flowers are pale violet.
invisible.gif Penstemon pinifolius can be grown with alpines; although it comes from the hot, dry areas of New Mexico and Arizona it thrives even in Scotland, where it has been long-lived. It makes a slowly spreading loose mat of stems, with bright green needle-like leaves, and has lots of narrow, tubular bright orange-red flowers.
invisible.gif Penstemon pinifolius 'Mersea Yellow' has bright yellow flowers.
invisible.gif Penstemon pinifolius 'Wisley Flame' is a low shrub, easily grown, spreading and layering as it goes, with tiny, linear, bright green leaves. The flowers are usually orange in this species, but in this form they are scarlet.
invisible.gif Penstemon serrulatus has whorls of blue-purple flowers.