The crocosmia (sometimes called montbretia) is a small genus of flowering plants that are part of the iris botanical family (iridaceae). This easy to grow plant flourishes with brilliant bright red, orange, yellow, or scarlet tubular flowers at the ends of arching stems.
The genus name is derived from two greek words; krokos, meaning saffron, and osme, meaning odor. This is because dried flowers, when crushed, emit a scent very similar to saffron when steeped in hot water.
This showy plant is highly prized for its sword shaped leaves and exotic looking flowers. Though they are native to the grasslands of Africa, they have become naturalized in many other regions around the world.
It’s always exciting to learn that even the most elegant and show stopping flowering plants aren’t all that difficult to grow. We cover many more specimens like this in our huge list of Beautiful Flowering Plants from all over the world. Go check it out after you’re done learning about the crocosmia!
What do Crocosmia Plants Look Like?
Crocosmia flowers are borne as colorful terminal inflorescences in the form of a cyme or a raceme. Each inflorescence grows at the end of horizontally arching stems and contains between 4 and 20 individual flowers.
Each crocosmia flower is a beautiful tubular shape and comes in warm colors like yellow, orange, red, and scarlet. The crocosmia flower is also hermaphroditic, meaning that it contains both male reproductive characteristics and female reproductive characteristics. Flowers bloom in the early summer and continue to bloom well into late summer or fall.
Though they are able to self pollinate, flowers are fertilized by beneficial insects and pollinators like bees, moths, butterflies, and hummingbirds. They can also be wind pollinated, where pollen is brought to the flower stamen through a steady breeze.
Though crocosmia flower inflorescences are enough of a reason to plant this specimen, they also come with beautiful foliage as well. Depending on the variety, crocosmias can be either evergreen or deciduous perennials.
This means that the plant will continue to bloom each year, but depending on the growing zone, it may keep its foliage green all year (evergreen) or it may lose its foliage as cold weather approaches (deciduous).
Crocosmia leaves are cauline and enisform in shape (sword shaped leaves). These long blades are parallel veined with smooth margins. Length will vary from species to species, though they all grow in clump blade forms.
Crocosmia plants grow from a basal underground corm. A corm is basically a bulbotuber that grows underground, and it stores important nutrients to help the plant survive through harsh winter temperatures or long summer drought.
Corms form as vertical chains, with the youngest and smallest growing closest to the top soil, and the oldest and largest growing at the end of the chain.
Corms are an interesting root system as they are contractile, meaning that the largest corm can drag the chain downwards, towards where conditions are most hospitable (where there is the most water and nutrients).
These corm chains can be quite fragile and are easily separated. New plants can grow from these individual corms, thus proliferating the entire population.
Though this quality enables the plant to thrive, they are as equally difficult to control, and are considered as an invasive species in certain regions.
What are some Crocosmia Varieties?
There are over 400 crocosmia cultivars, with the most widely cultivated being the crocosmia ‘lucifer which is a cultivar that has won the prestigious Award of Garden Merit from the Royal Horticultural Society. Another popular cultivar is crocosmia ‘star.
Giant Montbretia (Crocosmia Masoniorum)
The giant montbretia is a crocosmia variety that is native to South Africa. This is a wonderful perennial plant choice as it flowers in the late season when most other perennials are fading away.
This variety has the same attractive and elegant upward facing, bright red flowers at the end of an arching stem. The main difference being that they are the tallest crocosmia variety, usually reaching over 1.5 metres in height
Falling Stars Crocosmia (Crocosmia Aurea)
The falling star crocosmia is also sometimes referred to as a Valentine flower. It is native to eastern and southern Africa and commonly grows along riverbanks and shady forests.
This variety blooms from June through to August with beautifully bright red and orange flowers. They usually grow to be over 45 inches in height.
Zigzag Crocosmia (Crocosmia Paniculata)
The zigzag crocosmia is native to eastern and southern Africa and prefers to grow in wet areas, like along streams, marshes, and riverbanks.
This variety can grow to be up to 1 metre in height and produces flower spikes in a zig zag pattern. They bloom a deep orange or brown/orange color.
Where do Crocosmias Grow?
The crocosmia is a native plant to the grasslands of southern and eastern Africa, as well as South Africa towards Sudan. There is one species of crocosmia that is endemic to Madagascar.
Since they are such a resilient and cold hardy plant, they can be naturalized in USDA zone 6 through 9. They prefer to grow on wet sites, and can commonly be found growing near riverbanks, lakes, streams, and marshes.
More than 400 cultivars are now grown all over the world, specifically in the United Kingdom, Ireland, New Zealand, and the Pacific Northwest of North America as well.
How do you Grow a Crocosmia Plant?
If the crocosmia so far sounds like a plant you’d like to introduce to your garden or green space, we’re about to go over a few steps on how to accomplish just that! You needn’t be an expert gardener to get it right.
First things first is knowing the right time of year for growing crocosmia. Corms should be planted in the early spring after the danger of frost has passed. This will vary from region to region. Soil should be properly warmed before planting the bulb.
Next step is to pick the right place for your crocosmia patch. Pick a place in your garden that receives full sun, meaning a minimum of 6 hours of sunlight per day. They prefer to exist in fertile, humus rich soils.
Ensure to plant corms in the earth with the pointed end facing up. Place it 2-3 inches deep into the soil, 6-8 inches apart from one another, and at least 25 inches away from other plants (as their bulbotubers can interfere with other plants’ root systems).
Press the soil around the corms and water the area thoroughly. The final step of planting is to cover the area with a thick layer of dry mulch to help keep the soil moist and the corms protected. This also helps with weed proliferation.
If you live in a particularly cold area, crocosmia corms can be harvested and kept in a cool, damp place for the winter where they can be then planted the following spring.
What are the Growing Conditions of Crocosmias?
The most specific growing requirement of the crocosmia plant is its soil type. It prefers to grow in fertile and humus rich soils. Soil must be consistently moist and well drained. It will not perform well in hot and dry sites.
Crocosmias can tolerate both full sun and partial shade sun exposure. They tend to bloom most productively in full sun, though in hotter climates, crocosmia blooms will last far longer in partial shade or light shade.
The crocosmia plant should be watered once a week during its growing season. Rule of thumb is that soil should always be moist.
In zones 6 through 9, crocosmia corms can be left in the ground to bloom again the following growing season. In areas areas outside of those hardiness zones, they will be able to grow, but corms need to be dug up before the winter.
Since crocosmia already prefers to exist in soils that are rich in humus and fertile, they do not need extra fertilizer in these conditions.
In terms of pruning, maintenance only needs to be kept after the blooming season is over. Removing spent blossoms can help encourage new ones. Do this by cutting back the stem to where it meets a leaf.
Ensure not to cut the leaf away. Keeping leaves continues the photosynthesis process which sends nutrients to the corms, which will help for the following summers’ bloom.
All in all, crocosmia is a very easy plant to incorporate to a green space, and a relatively low maintenance specimen. The most important thing to remember is that they are not a drought tolerant plant, and soil needs to be consistently moist.
How are Crocosmia Plants Used?
Crocosmia plants are primarily used for their ornamental value. They not only sprout showy and exotic looking flowers that come in a variety of gorgeous warm colors, but they produce decorative foliage in the form of sword shaped leaves as well.
They make for a wonderful addition to a rock garden, as a border plant, as a container plant, and they can grow in pots too! They also make for a wonderful cut flower specimen, as blooms can last up to 3 weeks in a vase.
The extravagant flowers and sweet smelling nectar of the crocosmia plant attracts many beneficial insects and pollinators, like bees, wasps, moths, hummingbirds, and butterflies. This is not only good for the plant, but beneficial for the insect and bird species as well!