Hartweg's beardtongue

Hartweg's beardtongue: how do you recognise it?

Habit

Bushy, semi-evergreen perennial 60–80 cm high and about 50 cm wide, with upright stems.

Foliage

Narrow to lance-shaped, dark green, opposite; sometimes evergreen at the base.

Flower

Tubular bells of 4–5 cm on long spikes, from June to October.

Colour

From scarlet and red to pink and purple, often with a white throat.

Roots

Fibrous and fairly shallow; hates wet soil in winter.

Flowering: June–October · Sowing: February–March · Plants: May–June · Pruning: April

Why grow it?

• Flowers for months, from June to October, on long spikes of tubular blooms.
• Bumblebees and bees visit the flowers readily.
• Compact and upright: suits narrow borders, containers and small gardens.
• Goes well with ornamental grasses, roses and other sun lovers.
• Easy to grow from seed and often flowers in its first year.

Hartweg's beardtongue: where does it grow best?

• Full sun in a sheltered spot, preferably against a warm wall.
• Very free-draining sandy or loamy soil; heavy, wet clay in winter does it the most harm.
• Normal to fairly dry soil; it will not tolerate wet feet.
• Allow 40–50 cm between plants; plant 3 or 5 together.

Light

Sun

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Normal

Size

0.7 m tall, 0.5 m wide

Hardiness

Half hardy (to -10 °C): protect it in harsh winters

Goes well with

• Ornamental grasses: Fine stems make an airy whole with the upright flower spikes.
• Lavender: The same dry, sunny soil; the purple flowers match nicely.
• Coneflower: The same sunny spot, with flowers from July into autumn.
• Rose: Red and pink penstemons weave through the underplanting of roses.
• Sage: Purple spikes in the same sunny, free-draining soil.

Hartweg's beardtongue: when and how to plant it?

Plant in May–June.

1. Plant in May–June, once the last night frosts are over.
2. Dig a wide hole and mix heavy soil with sand or fine grit to improve drainage.
3. Set the plant at the same depth as in the pot and firm the soil.
4. Keep 40–50 cm between plants and water in generously at once.
5. Water regularly during the first season until it is well established.
6. Do not pile thick mulch against the stems; a thin layer of grit or bark is enough.

Care

Water

Water regularly in dry weather, especially in pots. Wet feet are worse than dry ones.

Feeding

Little: a bit of organic fertiliser in spring. Too much nitrogen gives lots of leaves and few flowers.

Deadheading

Cut faded spikes back to just above the next side shoot: this encourages new flowers.

Support

Usually not needed; tall plants can be supported with a few twigs.

Winter mulch

In November, lay dry leaves or bark around the base against frost and cold damp.

Pots

It does well in a pot with potting compost mixed with plenty of sand; repot in spring.

Tip: Do not cut back in autumn but only in April: the old stems protect the plant against frost. As insurance, take a few cuttings in August and overwinter them frost-free.

Hartweg's beardtongue: when to prune it?

Pruning months: April.

When: In April, when you see new shoots at the base. Not in autumn.

How:

• Cut the stems back to 10–15 cm above the ground, just above the new shoots.
• Remove dead and frost-damaged parts back to healthy wood.
• In summer, cut faded spikes back to the first side shoot.
• In autumn do not cut anything: the old stems protect the plant against frost.

Caution: Do not prune in autumn: open stems let water run down to the crown, which kills the plant in frost.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In August–September: take 8–10 cm cuttings from non-flowering shoots, cut below a node, root them in sandy compost and overwinter them frost-free. This way you are sure to keep plants.

Seed

Sow indoors in February–March at 15–20 °C; barely cover the seed. Prick out the seedlings and plant them out after the Ice Saints (mid-May). Cultivars do not always come true from seed.

Hartweg's beardtongue: how does it get through the winter?

Hardy to −10 °C: protect in harsh winters.

• Limited hardiness, down to about −10 °C: it may die in a hard or wet winter.
• Leave the old stems standing and lay dry leaves or bark around the base in November.
• Make sure drainage is good: wet soil is more dangerous than frost alone.
• In a pot: shelter it in frost or bring it into a bright, frost-free place.

Diseases and pests

• Frost-killed plant: In hard or wet winters it dies. Provide drainage, mulch in November and take cuttings in autumn as a back-up.
• Slugs: They eat young shoots in spring. Pick them off in the evening.
• Aphids: On young shoots and flower spikes. Rinse them off with water or let the ladybirds do the work.
• Few flowers: Too much shade or too much nitrogen. Put it in full sun and feed less.

Through the year

• February: Sow indoors at 15–20 °C.
• March: Prick out seedlings. Sow indoors.
• April: Cut back to 10–15 cm. Add compost.
• May: Plant out after mid-May. Watch for slugs.
• June: Flowering begins. Water in dry weather.
• July: Flowering. Cut off faded spikes.
• August: Flowering. Take cuttings.
• September: Flowering. Take cuttings and overwinter them frost-free.
• October: Last flowers.
• November: Lay dry leaves or bark around the base.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Penstemon comes from the Greek ‘pente’ (five) and ‘stemon’ (stamen): next to four stamens there is a fifth, sterile, often hairy one.
• The species name hartwegii honours Karl Theodor Hartweg, a German plant collector who gathered plants in Mexico in the 19th century.
• The genus has more than 250 species, almost all native to North America.