Madagascar Periwinkle
Catharanthus roseusUSDA | Grow Zone
10-11Outdoors all year in zones 10 to 11. Anywhere colder, keep it as a houseplant. Protect it below 50°F.
- Light
- Full sun, 6-8 hours
- Water
- When top inch is dry
- Humidity
- 40-60%
- Temperature
- 65-85°F (18-29°C)
- Difficulty
- Beginner
- Growth
- Moderate
- Mature size
- 2-3 ft tall, 1-2 ft wide
- Pets
- Toxic to pets and humans
Madagascar Periwinkle, or Catharanthus roseus, is a vibrant flowering plant native to Madagascar. Known for its beautiful blooms and medicinal properties, it is a popular choice for gardens and containers.
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Ideal temperature
65-85°F is where it grows fastest. Below 50°F cold damage starts.
Spacing and harvest
- Mature size
- 2-3 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
Catharanthus roseus prefers to dry out slightly between waterings.
Water thoroughly when the top inch of soil feels dry, typically every 7-10 days during the growing season. In cooler months, reduce watering frequency. Signs of over-watering include yellowing leaves and root rot, while under-watering can cause wilting and leaf drop.
Light
This plant thrives in full sun, requiring at least 6-8 hours of direct sunlight daily.
It can tolerate partial shade but may produce fewer flowers. Ideal placement includes south-facing windows or outdoor areas with ample sunlight.
Soil
Catharanthus roseus prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of potting soil, perlite, and sand works well to ensure good drainage. Avoid heavy soils that retain moisture.
Humidity
This plant prefers moderate humidity levels around 40-60%.
To increase humidity, consider misting the leaves or placing a humidifier nearby. Signs of low humidity stress include browning leaf tips and wilting.
Temperature
The ideal temperature range for Madagascar Periwinkle is 65-85°F (18-29°C).
It is hardy in USDA zones 10-11 and can tolerate brief periods of heat but is sensitive to frost. Protect from temperatures below 50°F (10°C).
Fertilizing
Use a balanced fertilizer with an NPK ratio of 10-10-10 or similar.
Fertilize every 4-6 weeks during the growing season and reduce or stop in the fall and winter. Signs of nutrient deficiency include yellowing leaves and stunted growth.
Pruning
Prune Madagascar Periwinkle in early spring to shape the plant and remove any dead or damaged stems.
Use clean, sharp pruning shears. Deadheading spent flowers encourages more blooms and maintains a tidy appearance.
Repotting
Repot every 1-2 years or when the roots outgrow the pot.
Choose a pot that is 1-2 inches larger in diameter. Signs it needs repotting include roots growing out of the drainage holes and stunted growth. Follow with fresh potting mix and water thoroughly after repotting.
Propagation
Propagation can be done through stem cuttings or seeds.
For stem cuttings, take 4-6 inch cuttings from healthy stems, remove lower leaves, and place them in moist potting mix. Keep the cuttings in a warm, bright location until roots develop, typically within 2-4 weeks. Seeds can be sown in spring after the last frost.
When it's unhappy
Yellow leaves
Why it happens
Over-watering or nutrient deficiency.
How to fix it
Adjust watering schedule and ensure proper drainage. Fertilize if nutrient deficiency is suspected.
Root rot
Why it happens
Excess moisture and poor drainage.
How to fix it
Allow the soil to dry out and repot in fresh, well-draining soil. Avoid over-watering in the future.
Wilting
Why it happens
Under-watering or extreme heat.
How to fix it
Check soil moisture and water thoroughly. Move to a cooler location if temperatures are excessively high.
Browning leaf tips
Why it happens
Low humidity or over-fertilization.
How to fix it
Increase humidity levels and reduce fertilizer application. Ensure proper watering practices.
Pest infestations (e.g., aphids, spider mites)
Why it happens
Weak plant health or environmental stress.
How to fix it
Inspect regularly and treat with insecticidal soap or neem oil as needed.
Care through the year
Spring
In spring, prune back any dead stems and begin a regular watering and fertilizing schedule as the plant comes out of dormancy.
Summer
During summer, ensure the plant receives full sun and adequate water, especially during hot spells. Monitor for pests and diseases.
Fall
In fall, gradually reduce watering as temperatures drop and prepare the plant for cooler conditions. Continue to remove spent flowers.
Winter
In winter, reduce watering significantly and keep the plant in a warm location. Protect from frost and avoid fertilizing until spring.
Toxicity & Safety
Catharanthus roseus is toxic to pets and humans if ingested. All parts of the plant contain alkaloids that can cause symptoms such as nausea, vomiting, and diarrhea. Keep out of reach of children and pets.
Good to know
Why are my Madagascar Periwinkle leaves turning yellow?
Yellowing leaves can indicate over-watering or a nutrient deficiency. Check the soil moisture and adjust your watering schedule accordingly.
How often should I water my Madagascar Periwinkle?
Water every 7-10 days, allowing the top inch of soil to dry out between waterings. Adjust frequency based on environmental conditions.
Can Madagascar Periwinkle grow in shade?
While it can tolerate partial shade, Madagascar Periwinkle thrives in full sun with at least 6-8 hours of direct sunlight for optimal growth and flowering.
How do I propagate Madagascar Periwinkle?
You can propagate through stem cuttings or seeds. For cuttings, take healthy stems, remove lower leaves, and place them in moist potting mix until roots develop.
What type of soil is best for Madagascar Periwinkle?
A well-draining potting mix with a pH of 6.0 to 7.0 is ideal. Consider mixing potting soil with perlite and sand for better drainage.
Is Madagascar Periwinkle toxic to pets?
Yes, all parts of the Madagascar Periwinkle are toxic to pets and humans if ingested, causing symptoms like nausea and vomiting.
When should I prune my Madagascar Periwinkle?
Prune in early spring to shape the plant and remove any dead or damaged stems. This encourages healthy growth and more blooms.
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