Hardy gloxinia

Hardy gloxinia: how do you recognise it?

Habit

Upright clump about 60 cm tall and 30 cm wide, with a thick, fleshy taproot.

Foliage

Dark green, glossy and divided into many leaflets, about 30 cm long; emerges late in spring.

Flower

Trumpet-shaped flowers 5–7 cm across, pink to rose-purple with a yellow throat, a few per stem, in May–June.

Seed pods

After flowering, long, narrow seed capsules form, containing winged seeds.

Roots

A thick, fleshy taproot that goes deep; it dislikes being moved.

Flowering: May–June · Plants: March–May · Pruning: March

Why grow it?

• Exotic-looking trumpet flowers in pink and yellow, which you would not expect in a Belgian garden.
• Flowers in May and June, as borders move from spring into summer.
• Attracts bees and bumblebees with its large flowers.
• Handsome dark green, divided foliage, even after flowering.
• Compact, upright habit: suits small borders and rock gardens.

Hardy gloxinia: where does it grow best?

• Full sun to part shade; it flowers most freely in sun, provided the soil does not dry out.
• Well-drained, humus-rich soil: sand or loam, acid to chalky. Heavy, wet clay is unsuitable.
• Average moisture in summer, but dry to moist in winter: standing water kills the roots.
• Sheltered from cold wind, for example in front of a warm wall or in a rock garden.
• Space plants 30 cm apart and mark the spot, because it emerges late.

Light

Sun and partial shade

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Normal

Size

0.6 m tall, 0.3 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Ornamental grasses: Fine stems as a soft backdrop for the large flowers.
• Hardy geranium: Blue or pink flowers in the same style and in the same position.
• Sage: Blue-purple spikes next to the pink trumpets.
• Lady’s mantle: A light, yellow-green edge at the front of the border.
• Lavender: Scent and colour that go well together in a sunny border.

Hardy gloxinia: when and how to plant it?

Plant in March–May.

1. Plant in March, April or May, when the soil is not frozen.
2. Dig a deep hole of at least 30 cm and mix in compost and some sand or grit for better drainage.
3. Set the plant so the crown sits about 8 cm below the soil surface; the fleshy root goes straight down.
4. Leave 30 cm between plants.
5. Water thoroughly straight away and then keep the soil lightly moist.
6. Mark the spot with a cane: the shoots appear only late in spring.

Care

Water

Regularly in dry weather during the first year. After that only in long dry spells; avoid wet soil in winter.

Feeding

In spring a thin layer of compost or an organic feed; no more is needed.

Mulching

A dry layer of bark or compost in autumn protects the crown from hard frost.

Deadheading

Trim faded flowers to extend flowering; later leave a few pods if you want to sow.

Leave undisturbed

Do not move it: the taproot is sensitive and the plant sulks for a long time.

Tip: Plant the fleshy root in spring about 8 cm deep, in a spot that does not stay wet in winter, and mark the place: it emerges late.

Hardy gloxinia: when to prune it?

Pruning months: March.

When: In March remove last year’s dead foliage; during flowering trim faded flowers.

How:

• Cut dead stems and leaves down to just above the ground in March.
• Remove faded flowers or flower stems, just below the flower.
• In autumn leave a few pods if you want to collect seed.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow fresh seed in spring or autumn in a cold frame or in a pot of sandy compost. It flowers after 2 years. The plants sometimes self-sow.

Division

In spring, as the shoots just emerge, detach a young shoot with a piece of root from the clump. Do this carefully: the taproot is fragile. Replant at once at the same depth.

Hardy gloxinia: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C as long as the soil is not wet: it usually gets through Belgian winters without trouble.
• In autumn, lay a dry layer of bark or leaves over the crown as protection against hard frost.
• Wet feet in winter are more dangerous than frost: make sure the soil drains well.
• In a pot: put it in a sheltered, dry spot and do not let it stand in water.

Diseases and pests

• Slugs: Young shoots are eaten in spring, before you even see them. Pick off slugs or lay a barrier of crushed shells.
• Root rot: The plant does not come up or collapses after a wet winter. Ensure good drainage and do not plant in heavy clay.
• Aphids: On young flower buds. Rinse off with water; ladybirds help.
• Not emerging: It comes up very late, often not until the end of May. Give it time and do not dig the spot over too early.

Through the year

• March: Clear away dead foliage. Plant. Apply compost.
• April: Plant. Mark the spot. Watch for slugs.
• May: The shoots emerge. Plant. First buds.
• June: Flowering. Trim faded flowers.
• July: Seed pods form. Water in dry weather.
• August: Collect seed if you want to sow.
• September: Sow in a cold frame.
• October: The foliage turns yellow and dies back.
• November: Cover the crown with dry mulch.
• December: Dormant.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The name Incarvillea commemorates Pierre d’Incarville, a French Jesuit and botanist who worked in China in the 18th century.
• The species name refers to Jean Marie Delavay, a French missionary and plant collector who sent plants from Yunnan to Europe in the 19th century.
• The hardy gloxinia belongs to the trumpet-vine family (Bignoniaceae), like the trumpet vine and the catalpa.