How to Stop Crocosmia Spreading and Take Back Control of Your Garden

You can plant crocosmia in pots or use a barrier to stop their spread if you don’t want them to spread too far in your garden. Alternatively, you can deadhead the flowers before they can set seed.

As a passionate gardener, I adore crocosmia. Their vibrant spikes of color livening up my garden beds in summer are always a welcome sight. However, as much as I love these fiery flowers, they do have a habit of spreading rapidly and taking over.

If left unchecked, crocosmia can quickly turn from a delightful addition to a rampant invader Their stolons creep stealthily under the soil, and seemingly overnight, a single clump becomes a thick carpet smothering everything in its path

Fortunately, with some knowledge and a little elbow grease, it’s possible to stop crocosmia in its tracks and reclaim your garden. Here are my top tips for controlling these creepy-crawly corms and preventing them from spreading out of control.

Monitor and Remove Unwanted Growth

Keep a close eye on your crocosmia patches, especially in spring and early summer when growth explodes. Remove any shoots sprouting up where you don’t want them It’s much easier to pull or dig out small clumps rather than waiting until they get established and form a tangled mat of corms and stolons

Check around the edges of existing clumps and thoroughly weed the surrounding area. Stolons can travel many feet underground before popping up, so be vigilant. Patrol farther afield too – I’ve found crocosmia shoots up to 20 feet away from the mother plant!

Cut Back Foliage in Fall

Chopping off the dying foliage in fall prevents the plant from photosynthesizing and storing energy in its corms for next year’s growth spurt. While this won’t kill the corms, it will weaken them and slow down their spread.

I use secateurs to snip the leaves and stems back to ground level once they start yellowing after bloom. Remove all greenery – don’t leave anything sticking up for the crocosmia to keep feeding on.

Dig and Divide Overgrown Clumps

Every three to five years, dig up the dormant corms in early spring, break them up into individual corms and replant in smaller groups. This helps reduce their vigor and restricts how far they can spread via stolons.

Use a garden fork to lift the clump out carefully, trying not to break up the chain of corms. Gently tease apart the corms or cut the stolons with a sharp knife. Replant only a few corms together, spacing the groups at least 18 inches apart. Discard excess corms or give them to gardening friends (make sure to warn them about the spreading habit!)

Grow in Containers

For very aggressive spreaders like the cultivars ‘Lucifer’ and ‘George Davison’, I recommend growing them in containers. This restricts the stolons and prevents rampant spread.

Plant a few corms in a roomy pot with drainage holes using a quality potting mix. Situate the container in a sunny, well-drained spot. One pot per variety is plenty – crocosmia will quickly fill out its allotted space.

Use Physical Barriers

Installing physical barriers can help impede those questing stolons. Try sinking a vertical root barrier or plastic edging around clumps to contain them. Or plant in a sunken bottomless bucket or pot with just the foliage poking out the top.

For mass plantings, lay thick black plastic under the soil surface to block stolon growth. Just be sure to leave access points to reach in and dig up the clump occasionally.

Choose Less Invasive Varieties

Crocosmia cultivars vary widely in their wandering ways. If you love the look but hate the spread, try these better-behaved options:

  • ‘Solfatare’ – sulfur-yellow flowers on short stems
  • ‘Severn Sunrise’ – glowing apricot blooms on compact plants
  • ‘Star of the East’ – low-growing with orangey-red flowers

The species Crocosmia masoniorum is another non-spreading alternative that opens its orange and yellow blooms sequentially for a longer display.

Be Ruthless!

Finally, don’t be afraid to be brutal if crocosmia invades planted beds or borders. Rip it out, corms and all, if it’s encroaching on areas you want clear. Replant with other perennials that can outcompete it, like daylilies or ornamental grasses.

Keep removing regrowth for a season or two and it will eventually die out. Just stay vigilant to prevent it creeping back from any remaining traces of corms or stolons.

While crocosmias are fabulous plants, their enthusiastic spreading habit can quickly get out of control. With constant monitoring, regular digging and dividing, and implementing barriers, you can keep them contained and enjoy their fiery floral displays without them taking over your garden.

It may seem like an endless battle against the creeping crocosmia, but with persistence and determination, you can gain the upper hand. Just remember to enlist help from family or friends when tackling large infestations – reining in a jungle of unruly crocosmia is definitely a two person job!

Here is some more information for you:

Crocosmia is a genus of perennial plants in the Iris family, native to Africa. They are often grown for their showy, brightly coloured flowers that bloom in the summer. A lot of people choose crocosmia plants for gardens and landscaping projects because they are simple to grow and take care of.

Most crocosmia plants are between 1 and 4 feet tall and have sword-shaped leaves and tall, arching stems. The flowers grow in groups at the top of the stems. Most of the time, the flowers are bright orange or red, but some species have yellow or pink flowers. Crocosmia plants are also known for their pretty seed pods, which keep the garden interesting even after the flowers are gone.

Crocosmia plants prefer full sun to partial shade and well-draining soil. They are typically planted in the spring or fall and should be watered regularly until established. Crocosmia plants don’t need much care and don’t need to be pruned much. However, cutting off the spent flowers can help the plant produce more flowers. They are also resistant to most pests and diseases.

Crocosmia plants are mostly grown for their pretty looks and are often used in beds, borders, and container gardens. They are also popular as cut flowers and are widely used in floral arrangements and bouquets. Additionally, some types of Crocosmia are used as medicine in traditional African medicine to treat a wide range of illnesses.

Crocosmia is a colourful and easy-to-grow plant that provides a burst of colour in the summer garden. People who garden and florists both like them because of their brightly colored flowers and pretty seed pods.

Did you find this answer useful? Subscribe to our newsletter for gardeing news, projects, special offers and competitions.

Here are some related questions:

You can ask one of our experts for help if you can’t find what you need on the website. To get in touch with us Click Here.

We will try to get back to you with an answer as soon as we can.

Crocosmia lifting and splitting in autumn – Burncoose Nurseries


How to keep crocosmia from spreading?

The primary solution is to thin out the planting. Crocosmia is a very vigorous, fast growing bulb that reproduces and spreads rapidly.

What is the problem with crocosmia?

Bulb/rhizome rot – Diseases of crocosmia include this bacterial disease, which occurs in wet, poorly drained soil and spreads quickly in warm, humid weather. Symptoms include stunted growth and yellowing leaves.

How to stop crocosmia flopping?

Apply a thick layer of mulch and fertiliser to soil during the Spring and Autumn seasons to prevent moisture loss. Water regularly while the plant is growing, but once it has grown do not water often. In wet areas, Crocosmia can start flopping. If this occurs, simply prop up the plant with a twiggy stick or wire frame.

How do I get rid of crocosmia?

Re: Montbretia/Crocosmia… Its the tiny corms that are a pain. Miss a few and the whole lot comes back again. If you dig the worst out, the only other thing you can do is treat it with a glyphosate weed killer when it sprouts next spring.

How to keep Crocosmia from taking over your garden?

By pulling up some of the plants, you’ll give the others room to flourish. You can also spread a thick layer of mulch around the base of the plants to help inhibit their growth. With a little bit of effort, you can easily keep crocosmia from taking over your garden.

What is the treatment for teratozoospermia?

Teratozoospermia is defined as the abnormality of sperm morphology. It means, it is a condition of irregular shape and size of the sperm that affects the fertility of a man. According to the criteria released by the World Health Organisation (WHO) in 2010, if the normal spermatozoa percentage in the ejaculate is less 4%, then a man is said to be having teratozoospermia condition. Mild to moderate teratozoospermia caused due to other reason might be reversible with timely intervention and some lifestyle changes such as quitting smoking and drinking alcohol, a well-balanced diet can improve sperm quality. If the abnormal sperm is a result of varicocele condition, immediate surgical correction can reverse the production of abnormal sperms with altered morphology. In the case of genetically inherited teratozoospermia, there is no cure. Defects in sperm morphology due to Cancer chemotherapy and radiotherapy are also difficult to cure. So, better to freeze your sperm before treatment is a good choice if future fertility is desired.

Can you get rid of Crocosmia?

Crocosmia bulbs cluster together, so you’ll need to dig deep and carefully to remove them.Ensure you extract all the bulbs, as even a single one left behind can sprout into a new plant.Dispose of the bulbs

How does Crocosmia spread?

Crocosmia spreads primarily through its corms, which are underground storage structures that resemble bulbs. The corms grow and divide over time, forming new corms that can produce new shoots and flowers. In the wild, crocosmia can also spread through the seed that it produces.

Leave a Comment