Red crocosmia

How to grow crocosmias

Find out all you need to know about growing crocosmia, in this detailed Grow Guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Plant
Plant

Do not Plant in January

Do not Plant in February

Do not Plant in March

Do Plant in April

Do Plant in May

Do Plant in June

Do not Plant in July

Do not Plant in August

Do not Plant in September

Do not Plant in October

Do not Plant in November

Do not Plant in December

Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does not flower in June

Plant does not flower in July

Plant does flower in August

Plant does flower in September

Plant does flower in October

Plant does not flower in November

Plant does not flower in December

Divide
Divide

Do not Divide in January

Do not Divide in February

Do Divide in March

Do Divide in April

Do Divide in May

Do not Divide in June

Do not Divide in July

Do not Divide in August

Do not Divide in September

Do not Divide in October

Do not Divide in November

Do not Divide in December

Crocosmias are guaranteed to spice up your borders with their small bright flowers in zingy citrus shades.

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There are hundreds to choose from, in varying sizes, so they’ll suit gardens of all sizes. The foliage is also very ornamental – the clumps of upright, strappy, bright green leaves are great for punctuating mixed borders. The sprays of flowers that follow appear from June onwards, into late summer and are good for cutting. Although if left, the small seedpods can be quite decorative.

Crocosmias are also known as montbretia, although this tends to refer to the common species Crocosmia x crocosmiiflora that has naturalised in many areas, and is considered to be invasive. The cultivated varieties are less likely to become invasive.

Take a look at our handy crocosmia Grow Guide, below.


Where to grow crocosmias

Crocosmia tubers
Crocosmia corms ready for planting

Crocosmias are South African in origin, and require fertile, well-drained soil. They prefer full sun, but will tolerate light shade. Although they love warmth, they also need a reasonable amount of moisture, so make sure that you choose a spot with well-cultivated soil that doesn’t dry out. In colder parts of the country, choose a sheltered site.


Planting crocosmias

Planting crocosmia corms
Planting crocosmia corms

Crocosmias are corms and can be planted like bulbs. Dig a generous hole, about 7-10cm deep and add a spadeful of well-rotted compost. Plant a handful of corms a few centimetres apart so that you start out with a reasonable clump and cover with soil.


Propagating crocosmias

Crocosmia x crocosmiiflora 'Star of the East'
Crocosmia ‘Star of the East’

If you want to increase your stock of crocosmia, lift clumps in spring. The corms multiply over the years and when you dig them up you will find a distinctive string of conjoined corms. Gently pull this apart and plant up the top two which will be the newest and therefore make the most vigorous plants.


Crocosmias: problem-solving

Crocosmias can succumb to red spider mite, but are otherwise generally pest and disease-free.


Caring for crocosmias

Crocosmia 'Lucifer'
Crocosmia ‘Lucifer’

Mulch crocosmia corms in autumn to protect them over winter and keep well watered during dry spells through the summer. Crocosmia corms multiply readily, so clumps will become congested and flower less vigorously over time. The best time to divide congested clumps is in spring. Watch our video on splitting up a clump of crocosmia.


Crocosmia varieties to grow

Crocosmia 'Citronella'
Crocosmia ‘Citronella’
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  • ‘Emily McKenzie’ – a compact crocosmia. The bright orange flowers have an attractive mahogany throat. Foliage is a slightly darker green and it can be slightly less hardy than other varieties
  • ‘Citronella’ – with upright, fresh green leaves and small, soft yellow luminous flowers
  • ‘Hellfire’ – bears tight clusters of enormous, bright crimson flowers from mid-summer to autumn
  • ‘Lucifer’ – with tall, arching sprays of intense, fiery red blooms. The first true red cultivar, ‘Lucifer’ is one of the tallest varieties growing up to 1.5m. The pleated leaves are also attractive in their own right and the seedheads can look decorative if left
  • ‘Harvest Sun’ – a relatively new hybrid, bearing large orange-red flowers in contrast with upright, fresh green foliage
  • ‘George Davison’ – at 60cm, this medium height crocosmia bears upright stems of golden yellow, freesia-like flowers from late-summer to autumn