Fragile, not always hardy or very hardy, penstemons are still essential in flower beds in summer because they bloom for a long time, in bright and varied colours, provided the soil remains cool.
What there is to know :
Botanical name : Penstemon
Common name : Penstemon , galane (very little used name)
Family : Scrophulariaceae
Height x spreading: 40 to 60 cm high x 50 cm spreading
Foliage : A tuft of stiff stems grows very quickly, covering itself with opposite lanceolate leaves.
Flowers : From June to October, short stems appear which are constantly renewed, each bearing dozens of tubular flowers open in two unequal lips in solid or two-tone shades: the heart of the flower is often lighter, even white. As soon as a flower stalk fades, a new one develops and replaces it.
Exposure : In full sun, but not scorching, sheltered from the wind. Hybrids need a mild climate, botanical species are more resistant to cold.
Soil : The Penstemon appreciates a good garden soil enriched with compost, light and well drained.
Hardiness : The stump freezes at -5°C, but it is more resistant to cold if the soil remains dry in winter.
- Plant young seedlings in spring (April-May) 40 cm apart. They will offer many flowers the following summer.
- If your soil is heavy, mix in plenty of sand and compost to lighten it.
- Choose a sheltered place to keep them longer.
Water regularly the first year to keep the soil cool and support flowering. Mulch to keep the roots cool.
In the following years, the Penstemons tolerate drought fairly well , requiring a few waterings only in times of drought.
Each year, at the beginning of spring, bring 1 to 2 handfuls of compost that you spread out at their feet. Pass the claw to incorporate it into the first centimeters of soil.
By cutting the young shoots of penstemons in half , you will force them to branch out and bloom more. Don’t throw away the cut shoots, cut them!
Protection against the cold
Penstemon strains are fragile. In cold regions, protect them with a thick cover of dead leaves. Keep a large winter veil handy to cover them as soon as the temperatures drop below freezing.
- Remove faded flowers regularly to encourage renewal and prolong blooming.
- Wait until the end of winter to clean the clumps: cut back the largest Penstemons fairly severely . The smaller ones do not need this pruning: they are satisfied with a light pruning carried out after flowering.
Multiplication of Penstemon
- In September, you can make a few cuttings of non-flowering shoots in a glass of water. Prick them out in a pot as soon as the roots appear and keep them under cover all winter. You can plant them the following spring.
- A division of the clumps is also possible, preferably in early spring.
- The sowing , little practiced, is also carried out in spring (March/April), in the heat. Store the terrine under a veranda or inside a frame, keeping the substrate moist. The seeds germinate in 10-15 days but require a minimum temperature of 20°C.
Flower Associations with Penstemon
With its long flowering period and varied flower colors, Penstemon goes well with many flowering perennials all summer and fall: Achilles, Heliopsis, Sauges, Coreopsis , Asters , Gauras , Valerians, perennial bellflowers …
Did you know ?
Cut flowers: The tubular flowers of Penstemon open out for more than ten days in a bouquet.
Varieties of Penstemons
There are 250 species of Penstemons , and many hybrids, all very elegant and colorful but unfortunately quite fragile:
This small, easy-to-succeed penstemon blooms in the spring (May to July). It naturally reseeds itself a lot in the sun when the soil pleases it. It forms a dense, not too tall clump of leaves that turn purple in winter and adorn themselves with lilac-blue flowers with white throats. In this species, there are two dwarf penstemon Penstemon hisutus pygmaeus, 20 to 40 cm interesting to use as a ground cover in the sun. They form a carpet of white flowers mixed with mauve hues.
Its small stalks of tubular flowers are bright red in June-July. Because of its small size and taste for warmth, you can plant it in a rockery, above a low wall or in a large decorative container. It is satisfied with little watering. Height: 10 to 20 cm
Penstemon barbatus coccineus
Native to the United States and Mexico like all other Penstemons, prefer this species if you live in a cold region because it is more rustic in addition to resisting drought well. Penstemon barbatus coccineus develops an erect tuft of glaucous leaves, covered with long branching stems of vermilion-red flowers. It flowers between May and July. Height: 1 to 1.20 m
Some hybrid Penstemons
A solid color:
- Evelyn , with soft pink flowers
- Garnet with red flowers
- Russian river, violet
- Midnight : one of the most beautiful Penstemons, vigorous, with generous purple flowers. Height 80cm
- White bedder : with white flowers that turn pink as they age. Height: 80cm
- Blackbird : with almost black flowers of great elegance Height: 80 cm
- Apple blossom: its soft pink flowers with white throat are later than average (early July), but this beautiful hybrid compensates for this defect by flowering until November Height: 50 to 60 cm
- Alice Hindley , with mauve flowers on a white ground. It is one of the earliest Penstemons since it often flowers from May until October. Height: 80 cm to 1 m.
- The lighthouse, bright red with white throat. Height: 80 cm to 1m
- Memories d’Adrien Régnier : a classic and vigorous penstemon, with soft pink flowers with a white throat. Height: 50cm
- Mother of pearl : with pinkish-white bells with a finely striped mauve-purple throat. Height: 80cm
- Sour grape : Its large mauve-violet flowers open onto a beautiful white throat.