How to Grow Vinca Seeds
Grow Guide #2399
Family: Apocynaceae
Binomial name: Catharanthus roseus
Life Cycle: Perennial
This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Vinca (Catharanthus roseus).
When to Sow Vinca Seeds
Vinca is a perennial plant that grows year round in most climates. Use the table below to identify the best time of year to sow vinca seeds in your climate.
JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Cool | ||||||||||||
Temperate | ||||||||||||
Sub-Tropical | ||||||||||||
Tropical | ||||||||||||
Arid |
Preparation
Vinca plants are perennial, meaning they live for several years. Choose a permanent position where plants can grow undisturbed by regular digging.
Vinca plants are best grown in full sun or part shade. Choose a location that will receive at least 3 hours of full sun each day.
Vinca plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.
Vinca plants can be grown in containers. If possible choose a variety that’s recommended for container growing. Use a good quality potting mix and make sure your container is large enough for mature plants; a minimum of 10 litres is recommended for vinca. During the growing season, keep in mind that container grown plants may need additional fertiliser to encourage healthy growth.
How to Sow Vinca Seeds
Vinca seeds do not require any treatment (eg soaking, stratification) before sowing.
Vinca seeds can be sown directly into the garden OR seedlings can be raised in trays or other containers and transplanted to the garden once established.
Sow Direct
- Sow seeds directly in the garden 2mm deep and 30cm apart.
- Keep soil moist but never wet or dry.
- Seeds should germinate in around 10-15 days at a soil temperature of 24-26°C.
- Young seedlings will need protection from pests, pets and weather until they are established.
Raise Seedlings
- Fill trays, punnets or jiffy pots with a good quality seed-raising mix, or use soil starter pellets.
- Sow seeds 2mm deep.
- Keep soil moist but never wet or dry.
- Seeds should germinate in around 10-15 days at a soil temperature of 24-26°C.
- Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall).
- Plant out, spacing plants 30cm apart.
Vinca is a tender crop that’s sensitive to frost. Do not transplant seedlings or sow seeds outside until all danger of frost has passed.
Optional: In cool climates vinca seeds can be sown indoors 6 weeks before the last expected frost. Grow them in a warm position with plenty of natural light.
How to Grow Vinca
Vinca plants are drought tolerant once established and grow best in soil that is dry and very well drained. Let the soil dry out between watering, and only water when the soil is dry about 10cm below the surface (test this by scratching away a little soil with your finger), even in summer. Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.
If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a high-potassium fertiliser or one formulated for flowering plants can be beneficial:
- Apply slow release fertiliser at the recommended rate when transplanting or when seedlings are 5-10cm tall.
- Apply liquid fertiliser at the recommended rate and frequency while plants are fruiting or flowering.
Optional: Pinch out the growing tips of vinca plants to encourage denser growth with stronger stems and more flowers. Using sharp secateurs or snips remove the top set of leaves, cutting just above a set of lower leaves.
Vinca plants should flower in approximately 85 days.
When plants have finished flowering prune them back to neaten them and encourage strong new growth. Using sharp secateurs or snips, cut individual stems just above a set of lower leaves.
Common Problems when Growing Vinca
Like all plants, vinca is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing vinca plants:
- Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
- Fusarium wilt and verticillium wilt are diseases caused by soil-borne fungi. The fungi enter a plants’ roots and prevent water and nutrients from moving through plants. Leaves and branches will wilt, dry off and die and leaves may yellow. There is no cure for wilt but choosing resistant varieties, disposing of affected plants and soil, practicing good garden hygiene and crop rotation will all help to prevent it spreading.
- Root rot is a disease caused by soil-borne fungi found in wet soil. Plants may be slow to establish, have yellowing or wilted foliage and have soft, brown tissue around the base of the stem and roots. Root rot is often fatal; remove and dispose of affected plants. Reducing soil moisture, adding organic matter to the soil and making sure mulch doesn't touch the stems of plants may help avoid root rot.
- Whitefly is a sap-sucking insect related to aphids. They are often found in large numbers on the underside of leaves and will swarm in clouds when disturbed. Plants may have yellowing leaves or may wilt, and growth will be slowed. Whitefly can be removed with a garden hose or sprayed with soap spray. Badly affected plants should be destroyed. Attracting beneficial insects that will prey on whitefly can be beneficial. Read more about managing whitefly here.