Orchid primrose

Orchid primrose: how do you recognise it?

Habit

Clump-forming perennial about 40 cm tall and 30 cm wide, with a leaf rosette at the base and upright flower stems. Often short-lived.

Foliage

Lance-shaped to oblong, 15–30 cm, light green and hairy; appears late in spring.

Flowers

Dense, cone-shaped spike of 5–10 cm with hundreds of small flowers, in June and July.

Colour

Red buds and calyces, with lilac to blue-purple flowers below. The flowers open from the bottom upwards.

Roots

Fibrous and shallow; it likes moist, well-drained soil and dislikes wet feet in winter.

Flowering: June–July · Plants: April–May

Why grow it?

• A very unusual flower: a spike with red buds and lilac flowers at the same time.
• Flowers in June and July, after the spring primulas.
• Bees and bumblebees visit the flowers.
• Suits a half-shaded border, a shade garden or a spot among ferns and hostas.
• Hardy to about −20 °C, as long as the soil does not stay wet in winter.
• Sometimes self-seeds, giving you new plants year after year.

Orchid primrose: where does it grow best?

• Half shade or light shade, preferably sheltered from the fierce afternoon sun.
• Humus-rich, moisture-retentive but well-drained soil: loam, clay or peat, acid to neutral.
• In summer the soil should stay moist; in winter it must not stay waterlogged.
• On heavy clay: mix coarse sand or fine grit and compost into the planting hole, or plant on a small mound.
• Allow 25–30 cm between plants, in groups of 3–5 for the best effect.

Light

Partial shade and shade

Soil type

Loam, clay or peat

Acidity

Acid or neutral

Moisture

Normal or wet

Size

0.4 m tall, 0.3 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Hosta: Large leaves that fill the space before the primula has come up.
• Ferns: Fresh green fronds in the same half shade.
• Columbine: Flowers at the same time in blue and purple.
• Hardy geranium: A soft ground cover in lilac or pink next to the red cones.
• Astilbe: Pink and red plumes in a damp spot.

Orchid primrose: when and how to plant it?

Plant in April–May.

1. Plant in April–May: it then has the whole summer to root before the wet winter.
2. Dig a hole twice as wide as the pot and mix in compost and a little coarse sand or fine grit.
3. Set the plant at the same depth as in its pot, with the centre of the rosette at soil level.
4. Plant in groups of 3–5, 25–30 cm apart.
5. Water in generously straight away and keep the soil constantly moist in the first summer.
6. Spread a layer of leaf mould around the plants and mark the spot with a cane, because it only appears at the end of May.

Care

Water

Keep the soil moist in summer, especially while in flower. In winter, wet soil is its worst enemy.

Feeding

A thin layer of compost or organic fertiliser in spring. No more is needed.

Mulching

A thin layer of leaf mould in spring keeps the soil cool and moist.

Spent flowers

Cut the stems off after flowering, or leave a few until the seed is ripe if you want seedlings.

Marking the spot

The plant dies down completely in winter and returns late. Mark the spot with a cane so you do not dig it up by mistake.

Slugs

Watch for slugs in spring: they love the young leaves.

Tip: Mark the spot with a cane in winter: it only appears at the end of May and is easily damaged then. Plant it in spring in well-drained soil and sow some more every couple of years, because it is short-lived.

Orchid primrose: when to prune it?

When: It is not pruned. Cut off spent flower stems after flowering and remove dead leaves in February–March.

How:

• Cut spent flower stems down to the base, unless you want seed.
• Leave a few stems until the seed capsules are brown and dry if you want it to self-seed.
• Remove dead, brown leaves in February–March, taking care not to damage the new buds in the centre.

Pruning calendar and basic rules

Propagation

Seed

Sow fresh seed in autumn or in January–March in a tray of seed compost, without covering it: it germinates in light. Put the tray outside in the cold and keep it moist; seedlings appear in spring and usually flower in their second year. Because the plant lives only a few years, sowing is the best way to keep it.

Division

Division is rarely needed and only works on older clumps in early spring, when the new leaves appear. Carefully split the clump into pieces with roots and replant them straight away.

Orchid primrose: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C, but wet winters are more dangerous than cold ones: make sure the soil is well drained.
• The foliage dies back and the plant is invisible in winter. Mark the spot.
• In a pot: keep the soil a little drier in winter and put the pot in a sheltered spot, for instance under a lean-to.

Diseases and pests

• Slugs: Holes in the young leaves in spring. Collect them in the evening and clear hiding places.
• Root rot: Plants wilt or die in a wet winter, especially on heavy soil. Provide well-drained soil and plant in spring.
• Vine weevil: The grubs eat the roots, especially in pots, and the plant suddenly wilts. Use nematodes against the grubs.
• Drought stress: Limp leaves and brown edges in a dry summer. Water and lay a layer of mulch.

Through the year

• March: Mark the spot. Remove dead leaves. Watch for slugs.
• April: Plant. Apply mulch.
• May: Plant. It appears at the end of May. Watch for slugs.
• June: Flowering begins. Water in dry weather.
• July: Full flower. Water in dry weather.
• August: Collect seed. Cut off spent stems.
• September: Sow. The plant goes dormant.
• October: Sow or put a seed tray outside.
• November: Plant dormant. Keep the spot free of wet leaves.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The species name vialii recalls Paul Vial, a French missionary who worked in China.
• The species was discovered in the late nineteenth century in Yunnan by the French missionary and plant collector Jean Marie Delavay.
• Unlike most primulas it has no tiers or umbel, but a dense cone: the red buds at the top are just as striking as the lilac flowers.