Crocosmia, Montbretia: Planting, Growing and Care

Botany

Crocosmias grow wild in grasslands along the eastern coast of South Africa. There are nine species, all native to South Africa except one, Crocosmia ambongensis, which is endemic to Madagascar. Horticulturists have created over 400 varieties of Crocosmia.

This plant gets its name from the Greek krokos: saffron, and osme: smell, because when the flowers are placed in warm water, they emit a strong saffron scent. Crocosmias are often known by the common name Montbretia, which more specifically refers to hybrid Crocosmias, particularly Crocosmia x crocosmiiflora.

Crocosmia belongs to the large Iridaceae family, which includes 1,800 species of mostly herbaceous plants. This cosmopolitan family (found on all continents) also includes Gladioli and Irises. These are typically geophytic plants, disappearing in autumn to overwinter underground thanks to storage organs (bulbs, corms…).

They reappear in spring. Crocosmia is very close to Tritonia, a genus that was formerly used as a synonym for Crocosmia.

Montbretia has an upright habit and forms clumps. It grows quickly and typically reaches 60 cm in height. The tallest varieties, like ‘Lucifer’, can even grow up to 1.20 m! It spreads easily via stolons, small horizontal stems that root upon contact with the soil to form new clumps. However, you’ll need patience for your plant to form a dense clump.

At the centre of the clump rise long, arching flower spikes, bearing terminal inflorescences composed of about twenty flowers. These are tubular, arranged horizontally in two rows. They come in shades ranging from intense red (‘Lucifer’) to yellow (‘George Davison’ or ‘Columbus’), through various orange hues. Some varieties, like ‘Emily McKenzie’, are even bicoloured.

Crocosmia offers a long summer flowering, from July until September-October. The flower measures about 3 cm in diameter and 2.5 cm long. It consists of six petals arranged in two rows (three inner and three outer). At the centre emerge three large stamens, all of equal length. These flowers are nectar-rich and attract butterflies.

It has very beautiful deep green leaves, upright and elongated in a lance shape. These leaves are arranged alternately on the stem (one after another). They resemble those of gladioli, also being long and pleated lengthwise. They can grow up to a metre long and 3 cm wide. The foliage is deciduous: it dies back in autumn and reappears in spring.

In autumn, to survive the winter, the plant forms corms, rounded and flattened bulb-like structures. These allow the plant to store reserves and regrow in spring. It’s a swollen stem, protected by small scales.

These corms grow in chains, one above another. There can be about ten in succession. New corms are at the top while older ones are buried deeper. Below the lowest corms, the plant has roots that allow it to anchor slightly deeper. The corms separate easily from each other, facilitating the plant’s spread (each corm can form a new plant).

Crocosmia’s fruits consist of three-lobed capsules, up to 1 cm long. They contain small brown seeds. They are decorative with their graphic appearance, resembling beads attached to the stems.

Crocosmia: botanical aspects

Montbretias are moderately hardy. Some very resistant varieties (like Crocosmia masoniorum) can withstand temperatures down to -15°C. But on average, they tolerate -10°C if protected by mulch. We recommend taking action in autumn to protect the bulbs by applying a thick layer of dead leaves, for example, or by digging them up to store them over winter.

The variety Crocosmia x crocosmiiflora is a hybrid created around 1880 by French nurseryman Victor Lemoine, by crossing Crocosmia aurea and Crocosmia pottsii. Cultivated worldwide, this hybrid has become invasive in California, New Zealand, the UK, Australia, Réunion…

Crocosmia thrives in maritime climates, quite mild and humid. In France, it does well along the Atlantic coast, particularly in Brittany and Normandy.

Species and varieties

Our Favourite Varieties

More Varieties to Discover

Botanical Species

Crocosmia Lucifer - Montbretia

This is our star variety, by far the most popular! This variety is a hybrid between the species Crocosmia masoniorum and Crocosmia paniculata, created by English hybridiser Alan Bloom in 1966. It boasts a stunning fiery red bloom and beautiful pleated foliage, glossy green. Hardy down to –12°C, it is more cold-resistant than most other varieties. It is also the tallest variety.

• Flowering time August to October
• Height at maturity 1 m

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Crocosmia Emily McKenzie - Montbretia

We love the originality of its bicoloured flowers, bright orange on the outer petals and deep red at the heart.

• Flowering time August to October
• Height at maturity 60 cm

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Crocosmia Columbus - Montbretia

This variety features beautiful golden-yellow flowers, around 3 cm in diameter, with a throat streaked with orange-red. The flower buds are orange, and the bracts are purplish.

• Flowering time August to October
• Height at maturity 50 cm

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Crocosmia Carmine Brillant - Montbretia

This is a fairly low-growing variety whose bright red flower buds give way to graceful orange-red and yellow-centred blooms. The stems are bronze-coloured. This variety has been awarded the Award of Garden Merit by the Royal Horticultural Society (RHS).

• Flowering time August to October
• Height at maturity 70 cm

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Crocosmia Solfatare - Montbretia

This Crocosmia displays graceful small yellow flowers, very bright, which contrast beautifully with the bronze-green foliage.

• Flowering time August, September
• Height at maturity 60 cm

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Crocosmia George Davison - Montbretia

This is a rather low-growing variety, ideal for borders. The orange flower buds reveal large bright yellow blooms. Early-flowering, it blooms sooner than others.

• Flowering time August to October
• Height at maturity 45 cm

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Crocosmia Buttercup - Montbretia

This variety is quite compact and offers a striking yellow bloom in beds.

• Flowering time August to October
• Height at maturity 60 cm

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Crocosmia Emberglow - Montbretia

Crocosmia ‘Emberglow’ has a warm, bright red bloom with an orange heart. This variety was created in 1970 and results from a cross between Crocosmia pottsii and Crocosmia paniculata.

• Flowering time August to October
• Height at maturity 60 cm

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Crocosmia Dusky Maiden- Montbretia

Crocosmia ‘Dusky Maiden’ features orange flowers with a lighter heart, a colour that contrasts well with its bronze stems and leaves.

• Flowering time February
• Height at maturity 40 cm

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Crocosmia Norwich Canary - Montbretia

This Crocosmia displays small, tubular yellow flowers, elegantly simple.

• Flowering time August to October
• Height at maturity 60 cm

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Crocosmia Zeal Tan - Montbretia

This rather low-growing variety features bright red flowers with a yellow heart. They are particularly highlighted by its dark green foliage.

• Flowering time August, September
• Height at maturity 60 cm

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These species exist in the wild, mainly in South Africa. They can be harder to source than horticultural varieties, except for Crocosmia masoniorum, which is fairly common in cultivation.

• Crocosmia masoniorum

With its bright orange flowers, this is undoubtedly the most beautiful of the botanical Crocosmia species. It reaches a height of 80 cm. Easy to grow, it is also hardier and more robust than other varieties, tolerating temperatures as low as –15°C. It is named after the American botanist Herbert Louis Mason (1896–1994). It originates from mountainous areas on the eastern coast of South Africa (Eastern Cape). Its distribution is quite limited, making it rare in the wild.

• Crocosmia paniculata

This species grows 1.20 m to 1.50 m tall and bears beautiful orange-red flowers, 6 cm long, on branched stems. Its leaves are strongly pleated and bright green.

• Crocosmia aurea

This species is common in the grasslands of the Cape Floristic Region in South Africa. It is found from South Africa to Sudan. It can reach 1.20 m in height. It blooms in branched inflorescences, each bearing up to ten large, bright orange flowers, 4 cm in diameter. Its lance-shaped leaves are 2 to 3 cm wide.

• Crocosmia pottsii

This species can grow 80 cm to 1 m tall. Its inflorescences bear up to 30 small orange flowers.

Planting

Where to plant?

Crocosmia thrives in full sun, where it will flourish most readily. However, it can tolerate partial shade. Feel free to plant it at the base of a south-facing wall.

Crocosmia prefers slightly acidic soils but also grows very well in neutral soil.

It enjoys moist ground that doesn’t dry out in summer and will thrive if planted near a pond. Still, ensure the soil is well-drained with sand or gravel. It prefers aerated, light soils. To protect its corms from rotting, avoid waterlogging in winter!

You can also grow it in pots, either as a standalone feature or paired with perennials or ornamental grasses. Choose a sufficiently large container, add gravel at the base for drainage, and plant it in a mix of compost, garden soil and sand.

Crocosmia in a flowerbed

When to plant?

The ideal planting period is in spring, during April-May, once the risk of frost has passed.

How to plant?

Corms are planted in the same way as bulbs. Start by working the soil to a depth of 15-20 cm. As Crocosmia appreciates rich soils, you can add compost or fertiliser. To improve drainage, incorporate sand, especially if your soil is heavy or clay-based. Plant the bulbs 8-10 cm deep (or up to 15 cm in colder regions), ensuring the pointed end faces upwards. Space them 10 cm apart to allow enough room for growth. We recommend planting them in groups for a more striking display—cluster around ten corms together in the same flowerbed. Cover with soil and water generously.

→ Discover our tips for growing Crocosmia in pots

Care and maintenance

Once planted, Crocosmia requires very little maintenance. Indeed, it is undemanding and has no specific diseases or pests. Just ensure you keep the soil moist and protect it from the cold during winter, as Crocosmia is only moderately hardy.

The roots of Crocosmia allow it to burrow deeper into the soil over time, making it slightly more frost-resistant as the years go by! The first winter is therefore the most delicate to get through—don’t hesitate to protect the plant in one of the following ways:

• If temperatures do not drop below –5°C (or if you’ve chosen a hardy variety like Crocosmia masoniorum…), simply apply a thick layer of mulch made of dead leaves at the base. Additionally, in autumn, when the foliage has dried, we recommend leaving it in place to protect the crown during winter rather than cutting it back for aesthetic reasons.
• If you live in a region where deep cold persists throughout winter, it’s wise to dig up the bulbs in autumn to protect them from frost. Store them in a dry, dark, and well-ventilated place, away from moisture to prevent damage. Check them regularly, as they may be nibbled by rodents or rot due to dampness. You can replant them in spring once all risk of frost has passed.

Crocosmia detests summer drought: the soil must remain moist, even in peak summer. To prevent the soil from drying out too much and reduce watering, we recommend protecting it with a layer of mulch. In any case, if you’ve planted Crocosmia in a pot, regular watering is essential. We suggest watering every ten days during the growing season if the weather is dry.

To prolong flowering, we recommend regularly removing faded blooms. This will encourage new flowers to develop.

Propagation

Crocosmia is easy to propagate. It regularly produces new corms, which you can collect to obtain new plants. If you don’t cut back the faded flowers, Crocosmia will tend to self-seed. You can collect the seeds and sow them, but they won’t produce plants identical to the original variety. Moreover, growing from seed means waiting a long time before achieving a substantial clump. That’s why we recommend buying bulbs or dividing existing plants instead.

Sowing

In autumn, once the seeds are harvested, you can sow them in pots or trays under cover. The process is quite simple. Place the seeds in a tray filled with pre-moistened compost. Cover with soil. Crocosmia may take 3 to 8 weeks to germinate. Keep the compost moist until the plants sprout. In spring, once the risk of frost has passed, you can transplant them outdoors. However, it will take 2 to 3 years for the plants to flower.

Seeds and a cross-section of a corm

Dividing corms

You can divide the corms in early spring, in March-April, before the plant starts growing. This can be done every three years to prevent overcrowding.

Crocosmia regularly produces stolons, from which new corms grow, stacked one above the other. Dig widely around the plant to avoid damaging the stolons and corms. Lift the clump and collect the new corms around the original plant. It’s best to leave each group of corms intact rather than separating them with a knife—the older ones will act as a nutrient reserve to support the growth of younger corms. Replant the new corm groups in a suitable location.

Conversely, if you want to control the spread of overly vigorous Crocosmia, separate the corms with a sharp knife. Preferably keep the younger ones, those on top. You can either discard the lower (older) corms or keep each one to maximise the number of plants. Replant and water well.

Association

With its vibrant and abundant flowering, the Crocosmia is a beautiful plant to include in an English-style mixed border. It will add an exotic touch to your flower beds. Pair it with other blooms in yellow-orange-red tones to create a highly colourful display! Rudbeckias, Gaillardas or Monardas will complement it perfectly! The red varieties are particularly suited to large gardens. They help draw the eye to a focal point in the garden and serve as a guide for visitors…

Crocosmia ‘Jackanapes’ and Phlox – Crocosmia ‘Lucifer’ and Veronicastrum virginicum ‘Fascination’

The slender leaves and airy blooms of the Crocosmia give it a graphic quality, allowing it to add volume to a flat or formally structured border. It can create a striking contrast when planted alongside more rigidly pruned plants. You could also pair it with white-flowering plants to soften the Crocosmia’s vivid colours.

For more planting inspiration, see our advice sheet: Crocosmia – 9 Successful Planting Combinations.