Swan Crocosmia
Crocosmia masoniorumUSDA | Grow Zone
7-10Outdoors all year in zones 7 to 10. Anywhere colder, keep it as a houseplant. Protect it below 40°F.
- Light
- Full sun to partial shade
- Water
- When top inch is dry
- Humidity
- 40-60%
- Temperature
- 60-75°F (15-24°C)
- Difficulty
- Intermediate
- Growth
- Moderate
- Mature size
- 3-4 ft tall, 1-2 ft wide
- Pets
- Non-toxic to pets
Swan Crocosmia, known for its vibrant flowers and sword-like foliage, is a stunning addition to any garden. Native to South Africa, it thrives in sunny locations and attracts pollinators, making it a favorite among gardeners.
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Ideal temperature
60-75°F is where it grows fastest. Below 40°F cold damage starts.
Spacing and harvest
- Mature size
- 3-4 ft tall, 1-2 ft wide
- Plant apart
- 12-24 in
- Frost
- Half hardy: light frost only
Everything it needs
9 essentials at a glance
Watering
Swan Crocosmia prefers consistently moist soil, especially during its active growing season in spring and summer.
Water thoroughly when the top inch of soil feels dry, typically every 1-2 weeks. Reduce watering in the fall and winter when the plant is dormant. Signs of over-watering include yellowing leaves and root rot, while under-watering may cause wilting and browning leaf tips.
Light
This plant thrives in full sun to partial shade, ideally receiving at least 6 hours of direct sunlight daily.
It can tolerate some shade, especially in hotter climates, but too much shade may reduce flowering. A location with morning sun and afternoon shade is often ideal.
Soil
Swan Crocosmia prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of loamy soil with added organic matter, such as compost, is recommended to ensure good drainage and fertility. Avoid heavy clay soils that retain water.
Humidity
This plant enjoys moderate humidity levels, ideally around 40-60%.
To increase humidity, you can mist the leaves or place a humidity tray filled with water and pebbles near the plant. Signs of low humidity stress include browning leaf tips and poor growth.
Temperature
Swan Crocosmia thrives in temperatures between 60-75°F (15-24°C) and is hardy in USDA zones 7-10.
It can tolerate some heat but may struggle in extreme cold, so protect it from frost during winter months.
Fertilizing
Use a balanced fertilizer with an NPK ratio of 10-10-10 during the growing season, applying every 4-6 weeks.
Reduce or stop fertilizing in the fall and winter. Signs of nutrient deficiency include yellowing leaves, stunted growth, and poor flowering.
Pruning
Prune Swan Crocosmia after flowering to remove spent blooms and prevent self-seeding.
Use clean, sharp pruning shears to cut back the flower stalks to the base. This encourages healthier growth for the following season.
Repotting
Repotting is typically needed every 2-3 years or when the plant becomes root-bound.
Choose a pot that is 1-2 inches larger in diameter than the current one. Signs that it needs repotting include roots growing out of the drainage holes and stunted growth. Gently remove the plant from its pot, loosen the roots, and place it in fresh soil.
Propagation
Propagation can be done through division or seeds.
For division, dig up the corms in early spring or fall when the plant is dormant, and separate them carefully. Replant the divisions in well-draining soil. For seeds, collect them after flowering and sow them in a seed tray, keeping them moist until germination occurs, usually in 4-6 weeks.
When it's unhappy
Yellow leaves
Why it happens
Over-watering or nutrient deficiency.
How to fix it
Check soil moisture levels and adjust watering frequency. Fertilize with a balanced fertilizer if nutrient deficiency is suspected.
Root rot
Why it happens
Excessive moisture and poor drainage.
How to fix it
Ensure the pot has adequate drainage holes and reduce watering frequency. If root rot is severe, repot the plant in fresh, dry soil.
Poor flowering
Why it happens
Insufficient sunlight or nutrient deficiency.
How to fix it
Move the plant to a sunnier location and consider fertilizing to boost nutrient levels.
Browning leaf tips
Why it happens
Low humidity or underwatering.
How to fix it
Increase humidity around the plant and ensure consistent watering to keep the soil moist.
Pests (aphids, spider mites)
Why it happens
High temperatures and low humidity can attract pests.
How to fix it
Inspect the plant regularly and treat infestations with insecticidal soap or neem oil.
Care through the year
Spring
In spring, begin watering regularly as the plant emerges from dormancy. Fertilize with a balanced fertilizer to promote growth.
Summer
During summer, ensure the plant receives full sun and keep the soil consistently moist. Deadhead spent flowers to encourage more blooms.
Fall
In fall, gradually reduce watering as the plant prepares for dormancy. Cut back spent foliage after it has died back completely.
Winter
In winter, protect the plant from frost by mulching around the base. Water sparingly, allowing the soil to dry out between waterings.
Toxicity & Safety
Swan Crocosmia is generally considered non-toxic to pets and children. However, ingestion of large quantities may cause mild gastrointestinal upset. Always monitor pets and children around plants.
Good to know
How often should I water my Swan Crocosmia?
Water your Swan Crocosmia every 1-2 weeks, allowing the top inch of soil to dry out between waterings. Adjust frequency based on seasonal changes.
Why are my Swan Crocosmia leaves turning yellow?
Yellow leaves can indicate over-watering or a nutrient deficiency. Check soil moisture and consider fertilizing if needed.
What type of soil is best for Swan Crocosmia?
Swan Crocosmia prefers well-draining soil with a pH of 6.0 to 7.0. A loamy mix with organic matter works best.
When should I prune my Swan Crocosmia?
Prune your Swan Crocosmia after flowering to remove spent blooms and encourage healthy growth for the next season.
How can I propagate Swan Crocosmia?
You can propagate Swan Crocosmia through division or seeds. Division is best done in early spring or fall when the plant is dormant.
What pests should I watch for on my Swan Crocosmia?
Watch for aphids and spider mites, especially in hot, dry conditions. Regular inspection and treatment can help prevent infestations.
What is the ideal temperature for Swan Crocosmia?
Swan Crocosmia thrives in temperatures between 60-75°F (15-24°C) and is hardy in USDA zones 7-10.
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