Catharanthus roseus (Madagascar Periwinkle)

What is Catharanthus roseus?

Catharanthus roseus, also known as Madagascar Periwinkle or Vinca, is a perennial plant often grown as an annual in colder climates.

Growth habit: It has a bushy and compact growth habit and forms dense mounds of glossy, dark green leaves.

Size: The plant generally grows to a height of 6-18 inches (15-45 cm) and spreads 6-18 inches (15-45 cm) wide.

Flowers: The plant produces an abundance of small, star-shaped flowers in various shades of pink, rose, red, white, and bi-colored patterns. They cover the plant from summer to frost.

Hardiness: Madagascar Periwinkle is hardy in USDA zones 10-11 but is often grown as an annual in cooler zones.

Garden uses: The plant is used in flower beds, borders, containers, and as ground cover.

Heat/drought: This periwinkle is heat-tolerant and drought-tolerant, making it suitable for hot, dry areas.

Pollinators: The flowers attract pollinators such as bees and butterflies.

Award: Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society.

Toxicity: All parts of the plant are toxic if ingested, posing a risk to pets and humans.

Deer/rabbit: The plant is generally resistant to deer and rabbits due to its toxicity.

Invasive: Madagascar periwinkle (Catharanthus roseus) can be invasive in some regions, particularly in warmer climates. It can spread rapidly by self-seeding and displacing native plants. Find where this species is invasive in the United States.

Why Should I Grow Madagascar Periwinkle?

Catharanthus roseus is a great choice for gardeners due to its ease of growth and low maintenance. This plant produces showy and vibrant flowers in a variety of colors, adding a pop of color and charm to any garden. Additionally, it has a long blooming season and is highly adaptable to various growing conditions, making it suitable for a wide range of garden styles and settings.

When to Grow Madagascar Periwinkle?

• Catharanthus roseus can be grown from seed or cuttings and should be planted in spring after the threat of frost has passed.

Where to Grow Madagascar Periwinkle?

• Sunlight: It is a warm-weather plant that requires at least six hours of direct sunlight per day. In hotter climates, it may benefit from some shade during the hottest part of the day. However, it is important to ensure that the plant still receives enough sunlight to produce blooms. If grown in too much shade, the plant may become leggy and produce fewer flowers.
• Soil: This plant thrives in well-draining soil that is rich in organic matter. It can tolerate a range of soil types as long as the soil is not compacted and drains well. Ideally, the soil should have a pH level of 6.0 to 7.0, which is slightly acidic to neutral. Before planting, it is recommended to amend the soil with compost or well-rotted manure to improve its fertility and drainage.
• Placement: It can be grown in garden beds, borders, or containers and is particularly well-suited for hot and dry climates.

How to Grow Madagascar Periwinkle?

• Prepare the soil by removing any weeds or debris and loosening the soil to a depth of about 8 inches (20 cm).
• Amend the soil with compost or well-rotted manure to improve its fertility and drainage.
• Sow the seeds about 1/4 inch deep, leaving about 12 inches (30 cm) between plants.
• Water the plant well after planting and keep the soil consistently moist but not waterlogged.

Care

Madagascar periwinkle is a low-maintenance plant that requires minimal care. Here are some tips for caring for this plant:

• Watering: Keep the soil consistently moist but not waterlogged. Water deeply once a week or more often during hot, dry weather.
• Fertilizing: Apply a balanced fertilizer every two to three weeks during the growing season to promote healthy growth and blooming.
• Mulch around the base of the plant to help retain moisture in the soil and suppress weeds.
• Pruning: Prune the plant to control its size and shape if necessary.

Pests and Diseases

Madagascar periwinkle is generally a hardy and disease-resistant plant, but it can be affected by a few pests and diseases. Here are some common issues and how to address them:

Aphids: These small, sap-sucking insects can be found on the undersides of the leaves. To control them, spray the plant with a strong stream of water, or use insecticidal soap.

Spider mites: These tiny pests can cause yellowing of the leaves and produce fine webbing. Spray the plant with water to remove them, or use an insecticidal soap.

Fusarium wilt: This soil-borne fungus can cause yellowing and wilting of the plant. To prevent it, avoid overwatering and improve soil drainage. Infected plants should be removed and destroyed.

Root Rot: This can occur if the soil is too wet, causing the roots to rot. To prevent it, ensure that the soil is well-draining and avoid overwatering.

Leaf spot: This fungal disease causes brown spots on the leaves. To prevent it, avoid overhead watering and space plants properly to improve air circulation. Infected leaves should be removed and destroyed.

By monitoring your Catharanthus roseus plants for pests and diseases and taking prompt action, you can keep them healthy and beautiful all season long.