Montbretia

Montbretia: how do you recognise it?

Habit

Upright clumps about 70 cm tall and 30 cm wide, which gradually spread.

Leaves

Narrow, sword-shaped and pleated lengthwise, fresh green, in fans.

Flower

Branched, slightly arching spikes with funnel-shaped flowers all facing one way, from July to September.

Colour

Orange, red, apricot or yellow, often with a darker centre.

Corm

Small, round corms; each year a new corm forms on top of the old one, creating chains.

Flowering: July–September · Plants: March–May · Pruning: March

Why grow it?

• Warm orange, red and yellow colours from July to September, when many borders are past their best.
• An elegant cut flower that lasts well in the vase.
• The sword-shaped leaves add structure from spring onwards.
• Easy and tough: it grows in sun or partial shade and in almost any soil.
• The seed heads stay decorative long after flowering.

Montbretia: where does it grow best?

• Sun or partial shade; it flowers most freely in full sun.
• Well-drained sandy, loamy or clay soil, acid to chalky, with some compost.
• Moist: the soil should not dry out in summer or stay wet in winter.
• Plant the corms 10–15 cm apart, in groups of ten or more.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.7 m tall, 0.3 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Sneezeweed: Warm shades of red, orange and yellow in the same late summer.
• Purpletop vervain: Airy purple flower heads as a contrast to the orange.
• Daylily: Similar leaves and flowers that carry the border through summer.
• Ornamental grasses: Swaying stems next to the arching spikes.
• Rudbeckia: Yellow flowers with a dark centre that complete the warm palette.

Montbretia: when and how to plant it?

Plant in March–May.

1. Plant the corms in March–May, when the ground is no longer frozen.
2. Loosen the soil and mix in some compost; add coarse sand to heavy clay.
3. Set the corms 8–10 cm deep, pointed end up.
4. Leave 10–15 cm between corms and plant them in groups for a full effect.
5. Cover with soil, firm lightly and water if the soil is dry. A layer of compost as mulch keeps the soil moist.

Care

Water

In long dry spells in summer, especially the first year. Dry soil means fewer flowers and red spider mite.

Feeding

A layer of compost in spring. Too much fertiliser gives lots of leaves and floppy stems.

Faded spikes

Cut them off, or leave them for the graceful seed heads.

Cut flowers

Cut the spikes when the lowest flowers open; the rest will open in the vase.

Division

Every 3–4 years in spring: it keeps flowering well and stays under control.

Tip: Plant the corms 8–10 cm deep in spring. It spreads quickly: divide the clumps every few years and keep it away from nature areas.

Montbretia: when to prune it?

Pruning months: March.

When: In March, before the new leaves appear. Leave the old foliage standing all winter.

How:

• Leave the dead foliage over winter: it protects the corms from frost and wet.
• In March, cut all old leaves and stems down to just above the ground.
• Cut off faded spikes in late summer if you do not want seed heads.
• When dividing, remove the old, shrivelled corms at the bottom of the chain.

Caution: Do not cut the leaves while they are green: the corm uses them to build up strength for next year.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April: lift the clump, pull the corms or small groups apart and replant them 8–10 cm deep.

Cormlets

Small corms can be planted separately; they flower after one or two years.

Seed

Possible in spring, but seedlings do not resemble the variety and take a few years to flower.

Montbretia: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Hardy to about −15 °C: in Belgium it usually survives without help, especially in free-draining soil.
• In cold, wet soil, cover the corms in autumn with a layer of leaves, straw or compost.
• Varieties with large or bronze leaves, such as ‘Solfatare’, are a little more tender: give them a sheltered spot.
• In a pot the corms freeze more easily: stand the pot against a wall and wrap it, or move it somewhere frost-free.

Diseases and pests

• Red spider mite: Finely speckled, bleached leaves in hot, dry summers. Water regularly and spray the leaves.
• Poor flowering: Usually clumps that are too dense or too much shade. Divide in spring and replant in a sunnier spot.
• Corm rot: The corms rot in cold, wet soil. Plant in free-draining soil and add coarse sand.
• Flopping spikes: In soil that is too rich or in a windy spot. Feed less and plant among other perennials that give support.

Through the year

• March: Cut off old foliage. Plant corms and divide clumps.
• April: Plant and divide. Add compost.
• May: Plant the last corms. New leaves are growing.
• June: Water in dry weather.
• July: Flowering begins. Cut spikes for the vase.
• August: In full flower. Water in dry weather.
• September: Last flowers. Keep or remove the seed heads.
• November: Leave the old foliage. Mulch on wet soil.
• December: Dormant. The dry foliage protects the corms.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The name Crocosmia comes from the Greek krokos, ‘saffron’, and osme, ‘smell’: dried flowers smell of saffron when you put them in warm water.
• Each year a new corm grows on top of the old one. This creates an underground chain of corms.
• The hybrid was raised around 1880 by the French nurseryman Victor Lemoine in Nancy, from a cross between Crocosmia aurea and Crocosmia pottsii.