Madagascar periwinkle

Madagascar periwinkle: how do you recognise it?

Habit

Compact, upright to slightly spreading little bush 25–35 cm tall and as wide.

Leaves

Opposite, oblong-oval, 3–7 cm, glossy dark green with a pale midrib.

Flower

Five flat, rounded petals above a narrow tube, 3–5 cm across, from June to October.

Colour

Pink, white, red, purple or lilac, often with a contrasting eye.

Toxicity

All parts contain poisonous alkaloids.

Flowering: June–October · Sowing: February–March · Plants: June · Pruning: June–July

Why grow it?

• Flowers from June into October, even in hot, dry summers.
• The glossy leaves stay fresh, even in full sun.
• Little work: the faded flowers drop off by themselves.
• Ideal for pots, containers and a warm spot against a south-facing wall.
• Copes with drought better than most summer bedding plants.

Madagascar periwinkle: where does it grow best?

• Full sun and warmth: the warmer it is, the better it flowers.
• Light, well-drained soil: sand or loam, acid to neutral.
• Dry to moderately moist; cold, wet soil makes the roots rot.
• A sheltered spot, for example against a south-facing wall or on a patio. Plant 25–30 cm apart.

Light

Sun

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Dry or normal

Size

0.35 m tall, 0.35 m wide

Hardiness

Frost tender: plant out after the last frost (mid-May)

Goes well with

• Moss rose: Bright flowers that also love heat and drought, in the same sunny container.
• Zinnia: Bright colours in the same warm, sunny border.
• Pelargonium: A sturdy summer flower for the same warm patio container.
• Ornamental grasses: Fine stems as an airy contrast to the glossy leaves.

Madagascar periwinkle: when and how to plant it?

Plant in June.

1. Sow indoors in February–March at 22–25 °C and cover the seed well, as it germinates in the dark.
2. Prick the seedlings out into pots and keep them warm and in good light; they grow slowly at first.
3. Do not plant out until June, when the nights stay mild too.
4. Set the plant at the same depth as in the pot, 25–30 cm apart, in well-drained soil.
5. Water in, then let the top few centimetres of soil dry out between waterings.
6. In a pot: use compost mixed with a little sand and a pot with a drainage hole.

Care

Water

Moderate: let the soil dry out a little between waterings. Water in the morning and at the base.

Feeding

In pots, a liquid feed for flowering plants every two weeks; in the open ground, a little compost is enough.

Deadheading

Not needed: the faded flowers drop off by themselves.

Pinching out

Pinch out the tips of young plants once for bushier growth.

Gloves

Wear gloves when pinching out and taking cuttings, and wash your hands afterwards.

Tip: Do not plant it out until June and water too little rather than too much: cold, wet soil is its worst enemy. In a pot on a warm patio it flowers most freely.

Madagascar periwinkle: when to prune it?

Pruning months: June–July.

When: Hardly any pruning is needed. Pinch out the tips in June and cut back long, bare stems a little in July.

How:

• Pinch out the tips of young plants just above a pair of leaves, for a compact plant.
• Cut back long, floppy stems by a third in July.
• Remove yellow or damaged leaves.
• Keep clippings away from children and pets and dispose of them straight away.

Caution: All parts are poisonous: wear gloves and do not leave clippings lying around.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow indoors in February–March at 22–25 °C, well covered. The seed germinates in 1–3 weeks; prick out when there are two true leaves.

Cuttings

In August, take tip cuttings 8–10 cm long, remove the lower leaves and root them in moist cutting compost under plastic in a warm place. Overwinter the young plants indoors.

Madagascar periwinkle: how does it get through the winter?

Hardy to 5 °C: protect in harsh winters.

• Not hardy: it cannot take frost and suffers below 5 °C.
• It is usually grown as an annual, sowing or buying new plants each year.
• It can be overwintered indoors on a bright windowsill at a minimum of 12–15 °C, with little water; the plants often become leggy, though.
• Bring potted plants indoors before the nights turn really cold, usually at the end of September.

Diseases and pests

• Root and stem rot: The plant wilts and the stems turn black at the base. Caused by cold, wet soil: plant out only in June and ensure good drainage.
• Yellow leaves: Too cold or too wet, or lack of nutrients. Water less and give some feed.
• Aphids: Small aphids on young shoots. Spray off with water.
• Red spider mite: Fine yellow speckling and webbing in hot weather, especially indoors or against a wall. Mist the leaves and give the plant more air.
• Whitefly: Small white flies under the leaves. Hang up yellow sticky traps and rinse the plant.

Through the year

• February: Sow indoors at 22–25 °C, covering the seed well.
• March: Sow indoors. Prick out seedlings.
• April: Keep growing the young plants on in warmth and good light.
• May: Put plants outside on warm days, but bring them in at night.
• June: Plant out in a warm, sunny spot. Pinch out the tips.
• July: Flowering. Trim back long stems a little. Water moderately.
• August: Flowering. Take cuttings to overwinter.
• September: Flowering. Feed pots.
• October: Last flowers. Bring pots indoors or clear the plants.

Edible and useful

Not edible. All parts of Madagascar periwinkle are poisonous: the plant contains dozens of alkaloids, including vincristine and vinblastine, which are used as cancer drugs and act powerfully on the body. Swallowing any causes vomiting, stomach ache and diarrhoea, and in larger amounts the nerves, blood and liver can be affected too. In folk medicine the plant is drunk as a tea for diabetes: never do this. Keep young children, cats and dogs away from the plant, wear gloves when pruning and taking cuttings, and wash your hands afterwards. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Did you know?

• It used to be called Vinca rosea but now has a genus of its own. Both do belong to the same family, the dogbane family.
• In the 1950s researchers extracted the alkaloids vinblastine and vincristine from it, which are still used in medicine today. Using the plant yourself is dangerous: it is poisonous.
• In the tropics it flowers all year round and has naturalised in many places.