How to Grow Crocosmias

Updated/Fact-Chacked on October 13, 2021 by John

My crocosmia is still flowering at the time of writing (mid-October) and will hopefully keep going for a few more weeks if the weather stays mild. Crocosmia produces a wonderful flower with a backdrop of architectural spiky foliage; varieties come in red, yellow and orange, flowering from late July through to the start of November.

Crocosmia are great for providing autumn flowers when everything else is dying back before winter sets in. Their exotic looking colours usually attract bees and other pollinators, which we like to encourage – look for the Crocosmia ‘Lucifer’ if you want a bee-loving crocosmia variety.

Crocosmia origin is from eastern Africa. They are related to gladiolas and have similar sword-like foliage. These plants

 They form clumps with beautiful, sword-shaped leaves and flowers.

How to Grow Crocosmia

Planting  Crocosmia 

Crocosmia are generally sold as corms; corms are similar to bulbs but all the nutrients are stored in the stem. Growing crocosmia from corms is similar to planting bulbs,  plant in a 10cm hole with some good compost and water in. Crocosmia corms are best planted in early spring in a sunny or partial sun location. Crocosmia prefer acidic soil but will thrive in any PH level. 

Crocosmia Maintenance

Crocosmia are simple to cultivate and care for. Once they are planted, you’ll be delighted with stunning flowers every season. Watering has an important factor, water once weekly during the summer months. To have fresh blooms, remove dead petals, prune the stems back to the area in which the leaves reach the stems. Preserve the leaves once the blooming season is done so that the plants can grow back into their bulb for next summer’s flowering. Consider reducing the foliage perhaps to the soil surface when the leaves wither and die down.

Crocosmias can grow 120 cm and can engulf surrounding plants, consider staking your crocosmia and using string as a support for them to lean on – this will make the foliage grow more upright.

Propagating crocosmia

Crocosmias can be a vigorous grower and take over an area it left unattended.  Divide your crocosmias every couple of years and give half to friends or plant in a new location. To propagate crocosmia, dig up clumps of crocosmia in the spring and carefully pull the corms apart and divide. The top two corms from each string should be planted first, as they will be the healthiest and thus the strongest plants.   

Growing Crocosmias Problems and Solutions

Crocosmias are susceptible to the red spider mite, but they are usually free from pests and disease. Some varieties are overly powerful and can spread aggressively, don’t buy an invasive variety.

Gladiolus rust also can impact crocosmia. Indications are blackish-brown or brownish-yellow specks that primarily occur on foliage but can also develop on petals. Low light and high humidity cause gladiolus rust. Pesticides, like sulfur powder or copper spray, are effective in early spring and when continued weekly all through the growing season but they can be ineffective when symptoms occur.

Crocosmias Varieties to Grow in the UK

There are other varieties of crocosmia you can choose from when you want to add them to your garden. They are as follows:

Citronella Crocosmia

This variety has little, soft yellow dazzling flowers and tall, fresh green foliage. It’s perfect for swaths of flowering plants in the landscaped garden, and the blossoms are great for cutting.

Emily McKenzie Crocosmia

Emily Mckenzie has upright, mid-green sword-shaped foliage and a beautifully arching spray of star-shaped, bright orange blooms with crimson tips. It’s a little less sturdy than some other types.

Harvest Sun Crocosmia

Harvest Sun features enormous orange-red flowers against straight, fresh green leaves. It’s great for spreading across the landscaped garden in swaths, especially in warm or tropical areas. The blossoms are great for cutting. It’s a newly developed hybrid.

George Davison Crocosmia

This variety goes well with vibrant colours. It features aesthetic clumps and straight sword-shaped foliage, as well as stunning orange bud sprays that open into golden yellow blooms throughout mid to late summer.

Lucifer Crocosmia

This variety has stunning scarlet-red flowers on arching stems that lure hummingbirds in the summer. Crocosmia Lucifer bulbs grow in moist, fertile soils that receive full or partial sun.  Crocosmia might not bloom the first year, but it is a perennial that will reward you with brilliant flowers once rooted. Lucifer is among the tallest types which can grow up to 5 feet.

Hellfire Crocosmia

this is a large flower that bears vibrant red flowers in springtime. These outward-facing blooms are produced on arching stems that usually have a 3 feet height. This is an excellent choice for the nice and warm border, and perfect for trimming that has earned a Garden Merit Award. This is an excellent choice for the nice and warm border, and perfect for trimming that has earned a Garden Merit Award.

Bressingham Blaze Crocosmia

Bressingham Blaze is a 3 feet tall variety of crocosmia plants with long flower spikes of bright orange-red blooms with yellow centres. It blooms from the middle until the end of the summer.