Crocosmia Bulb Care: Tips For Growing Crocosmia Flowers

Crocosmia Bulb Care: Tips For Growing Crocosmia Flowers

By: Bonnie L. Grant, Certified Urban Agriculturist

Growing crocosmia flowers in the landscape produces masses of sword-shaped foliage and brightly colored blooms. Crocosmias are members of the Iris family. Originally from South Africa, the name comes from the Greek words for “saffron” and “smell.”

Learning how to plant crocosmia bulbs can give your garden dimension and sunrise colors of red, orange and yellow, and the funnel-shaped blooms have a subtle scent that increases when they are dried.

Crocosmia Plants

Crocosmia blooms are produced on slender stems of 2 feet (0.5 m.) or more in length. The flowers appear in May or June and the plant will keep producing all summer. Crocosmia flowers make excellent cut flowers for indoor arrangements.

These plants are hardy in USDA Zones 5 to 9. Crocosmia plants may become invasive over time and require a large space, but there are 400 cultivars to choose from, some of which have a slower spreading rate. The green leaves may be rippled or pleated and are an attractive sight in the garden even before the flowers form.

How to Plant Crocosmia Bulbs

Crocosmia plants grow from corms, which are closely related to bulbs. Growing crocosmia flowers from corms is not different from planting bulbs. Both are simply underground storage organs for a plant, which contain the nutrients and embryo necessary for the plant to sprout. Corms differ from bulbs by the lack of rings on the interior but otherwise function in a similar manner.

Crocosmias prefer slightly acidic soil. Make sure the garden bed is nutrient rich and well-drained, but lightly moist.

Plant the corms in spring about 6 to 8 inches (15-20 cm.) apart at a depth of 3 to 5 inches (7.5-12.5 cm.). Plant them in clusters for maximum effect. The corms will naturalize, or produce offsets, over time.

Plant crocosmias in full to part sun for best results.

Crocosmia Bulb Care

Once planted, little is needed in the way of crocosmia bulb care. The corms are hardy and rarely need to be lifted for winter except in areas below USDA Zone 5. In these areas, plant them in pots and then move the pots to a sheltered location for winter storage. You can also dig them up, dry the bulb and store where temperatures are moderate over the freezing period. Then plant them anew when soil temperatures warm up.

Division can be done in early spring, by lifting the clumps and cutting apart sections of the grouped corms. Replant these in other areas for more of the bright, appealing flowers.

Crocosmia plants have few pest or disease problems and require no special maintenance. They are an easy addition to the home landscape and attract hummingbirds and pollinators.

Crocosmia flowers are harvested for cutting when the lower blooms have just begun to open. Hold the stems in 100 F. (38 C.) water in a dark place for 48 hours. This increases the length of time the flowers will stay fresh in a cut floral display.

Growing and caring for crocosmias is easy and once planted, you’ll be rewarded by beautiful blooms each year.

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Official Plant NameCrocosmia
Common Name(s)Crocosmia ‘Lucifer’ / Montbretia
Plant TypePerennial Flower
Native AreaSouth and East Africa
Hardiness RatingH5
ToxicityMildly toxic to pets
FoliageSword-shaped leaves, herbaceous
FlowersFunnel-shaped flowers in bright reddish-orange
When To SowApril, May, June
Flowering MonthsJuly, August, September
When To PruneOctober, November
Sunlight

Preferred
Full Sun / Partial Shade

Exposure
Exposed or Sheltered

Height
1 – 1.5M

Spread
0.1 – 0.5M

Bloom Time
July – September

Preferred
Most Soil Types

Moisture
Moist but well drained

Crocosmia ‘Lucifer’ is the most widely grown variant of Crocosmia – a deciduous perennial with narrow, sword-shaped leaves and vivid tubular flowers.

In the case of the Lucifer cultivar, these flowers are bright red, and the plant grows to around 1.2 metres tall.

C. Lucifer is easy to grow in the UK, as it’s hardy to our climate and can withstand harsh winters and temperatures down to -15°C. The plant doesn’t require pruning, and the ease of growing and reliability of flowering makes it a popular choice for new and seasoned gardeners alike.

It is most often found in flower beds and herbaceous borders, where it complements other flowering plants, and is a great way to add tropical colour to your garden in late summer, once the spring bloomers have come and gone. It also provides attractive, mid-green foliage from spring to autumn.

If Crocosmia ‘Lucifer’ has spiked your interest, then read on for our best care and growing tips, for everything you need to know about how to conjure this devilishly red, pointy-leaved perennial into your garden.


Cut-Flower Tips

Crocosmia's arching stems make it a unique addition to any flower arrangement. Give this plant extra care right after cutting and it will last for more than a week in a vase. First, cut stems when the first few flowers at the bottom of the spike are just opening. Remove the leaves from the stems and recut them. Immerse the stems in warm water up to the point where the flowers emerge. Place the vase in a cool, dark place for 48 hours, then move it to a bright spot and enjoy your handiwork.


Crocosmia: Why We're Featuring This Plant

Crocosmia is a beautiful, summer bloomer that you should add to your garden for many reasons! Our Crocosmia plant profile will explain more!

You could say this star in the garden "captivated" our attention long ago with its uniqueness and beauty. T

First, the design. Imagine groups of orange, red, or pink trumpet-shaped flowers. These flowers are clustered at the end of tall stems which are surrounded by upright, sword-shaped leaves protruding out of the ground. Wow! This alone can give your garden a whole new tropical and unique look. Your neighbors will be asking you where you bought these amazing plants and sneak looks at your yard when you're not looking!

Second, did you know that the crocosmia will attract hummingbirds and all kinds of other pollinators? Pollinators are not able to resist this plant due to its shape and variety of colors. Read on to learn what else you can do to attract pollinators to your garden.

Finally, with its climatic growing range, the crocosmia is a perfect plant for your garden because it can thrive just about anywhere, in almost any zone (with a few exceptions, of course).

Another reason we choose crocosmia is due to its July bloom time in our zone 8b. The vibrant, spiky red blooms are equally welcomed by both us and the pollinators.

This plant profile below is meant for beginner gardeners but can be used by anyone who wants to learn more about this captivating plant.


Fill the seed tray with seed starting mix to within 1/4 inch of the rim. Water the soil until the water drips from the bottom of the tray. Allow the soil to drain completely.

Push the seeds 1/4 inch into the soil and barely cover with soil. Crocosmia seeds require light to germinate.

  • Feed your crocosmia with a good quality granular flowering bulb fertilizer in early to mid-spring after growth has appeared above the soil and once again in the summer.
  • Fill the seed tray with seed starting mix to within 1/4 inch of the rim.

Place the seed tray in an area that receives lots of light, but out of direct sunlight, and remains 68 to 70 degrees F. Keep the soil moist, not soggy, by misting it with a plant-misting bottle. The crocosmia seeds should germinate in two to four weeks.

Transplant the seedlings outdoors, in a sunny area, in late spring when temperatures are consistently above 65 degrees F.


Tips and Tricks for Planting Bulbs

To get your bulbs off to a good start and have them grow into vibrant plants, make sure they have good drainage. If the soil is constantly soggy, the roots will rot.

Getting good drainage in a pot or container is easy. Just make sure the pot has drainage holes, place gravel in the bottom of the pot and add soil.

In the garden or flowerbed, you can test for drainage by digging a hole that is 1-ft. deep and 1 ft. wide. Then fill the hole with water and record how long it takes for the water to completely drain. The ideal time is between 10 and 30 minutes. To improve your soil drainage, work lots of organic matter, such as aged manure, compost or peat moss into it.

If the soil has very poor drainage, you might want to consider growing bulbs in containers or raised beds.


Watch the video: Crocosmia, the colorful perennial with diabolical names - Gardening with Ciscoe