How to Grow and Care for Crocosmia (Coppertips)

Crocosmia, also commonly known as coppertips, is a perennial flower that grows tall pigment-rich blooms in the summer just when other spring bloomers are entering dormancy. Crocosmia grows best in somewhat drier climates with less humidity, full sun, and well-draining, slightly acidic soil. It thrives in mild summer temperatures but will need some shade in scorching hot and drying sun.

Crocosmia Care

• Plant crocosmia corms when the weather warms in spring and the danger of a spring frost has passed.
• Plant the corms at least 3 inches deep and 6 to 8 inches apart both to help them survive the winter and to help plants maintain an upright habit.
• Install grow-through plant supports to support the long foliage and flower stalks that tend to lay down.

Warning

Of the approximately 400 crocosmia cultivars, a few cultivars are known to be invasive. The named cultivars are less likely to be invasive than the straight species. Crocosmia × crocosmiiflora (Montbretia) along withC. masoniorum(Crocosmia‘Marcotijn’) and some forms of C. pottsiican spread readily.

Light

Crocosmia grows and flowers best in full sun. They will grow in partial sun conditions but won't flower as much as they do when planted in full sun. Some afternoon shade is fine in hot climates. If your partially shaded plants are reaching toward the sun, dig up the corms once the foliage has faded and relocate them to a sunnier location.

Soil

Crocosmia plants don't need to be pampered when it comes to soil, but good drainage is important. If your soil is comprised of heavy clay, amend the soil with sand and peat moss to create a well-drained, loose consistency. The alternative is to grow crocosmia plants in raised beds or containers.

Water

Crocosmia plants need regular watering, but you should not overwater them or root rot could occur. Water only when the top of the soil feels dry.

Temperature and Humidity

Although crocosmia tolerates high heat and humidity, it thrives in drier climates with mild temperatures. Perhaps too much of a good thing isn't desirable, according to gardeners in places like the Pacific Northwest, where these plants tend to take over the flowerbed.

Fertilizer

Crocosmia grows well in lean or rocky soils and doesn't need supplemental fertilizer. Excessive nutrients can cause an overgrowth of foliage at the expense of the blooms.

Types of Crocosmia

• 'Lucifer' is a blood-red variety developed in 1966. It is the most popular and hardiest crocosmia variety in the trade, surviving winters in zone 5.
• 'Bressingham Beacon' has bi-color orange and yellow flowers but isn't reliably hardy in USDA hardiness zones 5 and 6.
• 'Citronella' has cheerful lemon-yellow blooms.

Pruning

Cut down spent flower stalks, but don't remove crocosmia foliage until it dies back naturally at the end of the growing season and when it turns light brown. While it is still green, the foliage photosynthesizes energy back into the corms to produce next year's blooms.

Propagating Crocosmia

You can propagate crocosmia by removing the small offsets that form on the corms and planting them in a couple of easy steps. This division process not only yields more flowers but also increases the overall vigor of the plants because they can become crowded as do their cousins in the iris family.

1. Dig the corms in the spring just before new growth starts.
2. Separate the corms by hand.
3. Replant them 6 to 8 inches apart.

How to Grow Crocosmia From Seed

1. Collect seeds from the seed capsules that form up and down the flowering spike in the fall. The capsules will easily break apart with your fingers.
2. Save seeds in seed packets until spring and place packets in a cool, dry, dark area that consistently stays under 60 degrees Fahrenheit.
3. In the spring, nick them and soak them in water to help speed germination.
4. Plant seeds in the ground in sandy loam after all chances of frost have passed.

Potting and Repotting Crocosmia

Any commercial potting soil will do for your crocosmia. Plant the corms closely in a container of any material and with drainage holes and watch for the grassy foliage to emerge a few weeks after planting. If no blooms occur in the first season, your corms may be too small to flower, so leave them growing in place until the next season.

Overwintering

In their typical growing zones, crocosmia can be left in the ground for overwintering. A layer of mulch might help with peace of mind. In colder areas, dig up the corms and take them inside for storage in a cool, dry place during the winter months.

Common Pests and Plant Diseases

Crocosmia is generally disease-free except for cases where there is poor drainage that leads to root rot. However, spider mites can plague crocosmia plants, especially when dry conditions prevail.

How to Get Crocosmia to Bloom

How Long Does Crocosmia Bloom?

From May to midsummer and mid fall, crocosmia blooms for five to eight weeks. These flowers also make beautiful and long-lasting cut flowers. Cut stems for fresh flowers when the first few bottom flowers on the spike are opening. Remove leaves and recut the bottom of the stem. Stand the flowers in tepid water and leave them in a cool dark place for 48 hours to condition the blooms to last longer.

What Do Crocosmia Flowers Look and Smell Like?

Their red, yellow, or orange tubular blooms are displayed on long, arching stems—a favorite for attracting hummingbirds. The blooms open one at a time from the bottom of the stem. Their grass-like foliage adds billowy movement to the garden and is attractive all season. If the blooms come in contact with water, they may emit a subtle saffron-like fragrance.

How to Encourage More Blooms

To get the most blooms, make sure the corms are planted in a location that receives six to eight hours of sunlight per day. Ample watering, especially during times of drought, will help motivate blooms. Avoid fertilizing too much or you will encourage foliage but fewer blooms.

Deadheading Crocosmia Flowers

There is no need to deadhead crocosmia flowers after they bloom. They will rebloom on their own.

Common Problems With Crocosmia

This flower is typically low-maintenance. You may find a couple of problems to contend with. Watch for these signs.

Mottled Leaves

If you notice that the leaves of your crocosmia flowers are mottled, pale, or covered in a web-like material, there could be a spider mite infestation. To confirm, look at the underside of a leaf with a magnifying glass to find the pest and eggs. The mites are sucking sap from the leaves which gives it that appearance. Eliminate mites with insecticidal soap, neem oil, or use pesticides as a last resort.

Lack of Blooms

Keep in mind that crocosmia might not bloom during their first year because the corms are storing up energy preparing for future blooms. Several factors, such as sunlight and moisture, contribute to the lack of blooms if the plants haven't flowered by their second season.

From: thespruce