Hartweg’s beardtongue scores in beds and pots with charming tubular flowers in striking summer colors.
Profile of Hartweg’s beardtongue:
Scientific name: Penstemon hartwegii
Plant family: plantain family (Plantaginaceae)
Other names: –
Sowing time: pre-cultivated under glass from March; in bed after frosts
Planting time: spring
Flowering period: June to August
Location: sunny to partially shaded
Soil quality: sandy to loamy, nutrient rich, humus rich
These information are for temperate climate!
Use in: flowerbeds, bouquets, stand-alone, group planting, planters, borders, flower garden, roof garden, potted garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 8-10 (-9 to +4 °C / +15 to +40 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of Hartweg’s beardtongue
Plant order, origin and occurrence of Hartweg’s beardtongue
Hartweg’s beardtongue comes originally from Mexico. It belongs to the almost 300 species rich genus of beardtongues (penstemon), all of which come from North and Central America and is part of the plantain family (Plantaginaceae).
Characteristics of Hartweg’s beardtongue
The perennial Hartweg’s beardtongue reaches a height of up to 80 centimeters (32 in), but some varieties remain significantly smaller. The perennial grows in loose clumps, whereby a basal tuft of leaves is missing. Rather, the tuft consists of upright, leaf-bearing stems.
Typical for Hartweg’s beardtongue are evergreen, narrow-lanceolate leaves in a lush green shade, which are mostly arranged opposite, sometimes also crosswise opposite. The leaves are entire.
From June to August the flower panicles open in different colors, depending on the variety. The witty asymmetrical flower shape with the wide corolla tube and four round tips, is reminiscent of a thimble. Typical and eponymous are the five stamens, only one of which is clearly hairy. The flowers are extremely popular with insects.
The flowers develop into capsule fruits.
Hartweg’s beardtongue – cultivation and care
Hartweg’s beardtongue loves the heat and would like to grow in a sunny, at most partially shaded place. The perennial survives winter only in mild regions without protection.
The soil must be permeable, especially when it is wet in winter, Hartweg’s beardtongue causes problems. The substrate should also be well supplied with nutrients and rich in humus. A low-lime soil is preferred. Smaller varieties tolerate a poorer substrate.
Planting Hartweg’s beardtongue
Hartweg’s beardtongue is best planted in small groups of three to five specimens. The planting date should be after the frosts in mid-May. Good soil preparation is important, i.e. loosening, weeding and possibly mixing in compost or draining. The roots should have enough space in the planting hole. The seeds can be pre-cultivated under glass from March.
Penstemon hartwegii should only be watered when it is very dry.
In spring, fertilizer is applied, preferably in the form of compost, with the budding.
Withered plant parts are cut back continuously to extend the flowering period.
In autumn, pruning should be carried out close to the ground, because the evergreen plants react sensitively to stem breakage and damage to the dying shoots in general, for example with fungal attack.
High-growing varieties in particular are grateful for being tied to a support in exposed locations, especially when they are in full bloom. You can easily build such a perennial holder yourself.
Hartweg’s beardtongue seeds are best cultivated indoors from March. Propagation by cuttings is also possible. This can be done best at the beginning of autumn, but the wintering is often a bit complex, as it has to be in a bright and cool location.
Diseases and pests
Snails, aphids and nematodes occur above all in unsuitable site conditions.
A protection with brushwood is recommended if there is black frost expected. The winter hardiness should be higher, the less lime there is in the soil. If Hartweg’s beard grows in the pot, it should definitely overwinter without frost.
Use in the garden
Regardless of whether it is cultivated for one or more years: Hartweg’s beardtongue comes into its own on fresh to dry open spaces, beds or borders in combination with other perennials with similar requirements such as anise hyssop (agastache), but also as a filler for gaps. The perennials are mostly cultivated like annual summer flowers. They also look decorative in the vase as cut flowers.
The color spectrum of the varieties is between white, pink, red and purple.
- Penstemon hartwegii ‘Carmine Frost’ remains relatively small at 40 to 50 centimeters (16 to 20 in); the variety blooms in white and red
- The same characteristics apply to the variety ‘Picotee’
- The also small-growing variety ‘Polaris Purple’ flowers in a dark purple shade
- ‘Polaris Red’ blooms in an intense carmine red
- ‘Arabesque Orchid’ blooms opulently with white, pink-edged flowers