Moonflower

Moonflower: how do you recognise it?

Habit

Annual (perennial in the tropics) twining climber, 3–4 m tall and about 40–50 cm wide; winds around supports.

Leaves

Heart-shaped, 8–20 cm, sometimes with a few lobes; fresh green.

Flowers

Trumpet-shaped, white, 10–15 cm across with a long, greenish tube; opens in the evening. August–October.

Scent

Sweet and strong, especially in the evening and at night.

Seed

Round seed capsules with large brown seeds; the seeds are poisonous.

Flowering: August–October · Sowing: March–April · Plants: June

Why grow it?

• Flowers that open in the evening and smell sweet: a special moment by the patio or seating area.
• Races up to 3–4 m: covers an obelisk, pergola or fence in one summer.
• The heart-shaped foliage gives lush green structure even without flowers.
• In the wild it is pollinated by hawk moths (night-flying moths).
• Also suits a large pot with a trellis on the patio.

Moonflower: where does it grow best?

• Full sun in the warmest spot in the garden: a south or west wall, or the patio.
• Sheltered from wind and cold nights.
• Free-draining, humus-rich but not too rich soil: sand, loam or clay, acid to chalky.
• Normal moisture: water evenly without waterlogging; in a pot water often in summer.
• Give it a support of 3–4 m: strings, an obelisk, wigwam or trellis; plant 30–40 cm apart.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

4 m tall, 0.5 m wide

Hardiness

Frost tender: overwinter indoors (above 5 °C)

Goes well with

• Tobacco plant (Nicotiana): Also scented in the evening and goes with the white flowers.
• Heliotrope: Sweetly scented flowers for the same warm spot.
• Morning glory: A related climber whose flowers open in the morning, the counterpart of the moonflower.
• Lavender: Scented and sun-loving at the foot of the support.

Moonflower: when and how to plant it?

Plant in June.

1. Soak the seeds for 12–24 hours in lukewarm water or nick the hard seed coat lightly.
2. Sow indoors in March–April, 1 cm deep, one or two seeds per 8–9 cm pot, at 20–25 °C; they germinate in 1–2 weeks.
3. Put the seedlings in a bright, warm place and give them a cane or string for support.
4. Harden the plants off in May: put them outside for longer and longer.
5. Plant out in June, when night frost is over, 30–40 cm apart by a support and water straight away.
6. Spread a layer of mulch round the base to keep the soil moist.

Care

Water

Keep evenly moist; in dry weather and in a pot daily in summer. Water in the morning, at the base.

Feeding

Sparingly: too much nitrogen gives plenty of leaves and few flowers. From July a potash-rich feed, such as tomato feed, every 2–3 weeks.

Pinching out

Pinch out the tip of young plants of 20–30 cm so that they branch.

Support

Guide the shoots upwards; after that they twine around the support themselves.

Spent flowers

Remove them and the plant carries on flowering.

Tip: Plant it by a seating area or patio to enjoy the evening scent. Soaking or nicking the hard seeds speeds up germination a great deal.

Moonflower: when to prune it?

When: It is annual and is not pruned. Do pinch out the tips of young plants and trim overlong or damaged stems.

How:

• Pinch out the tip of young plants of 20–30 cm so that they branch.
• Cut off spent flowers and seed capsules to keep it flowering.
• Shorten overlong stems and tie them to the support.
• Remove the dead plant after the first frost.

Pruning calendar and basic rules

Propagation

Seed

Sow indoors in March–April at 20–25 °C; first soak the seeds for 12–24 hours or nick them lightly. They germinate in 1–2 weeks.

Collecting seed

In September–October let a few capsules ripen, if the summer was warm enough, and store the seed dry, cool and dark for next year.

Moonflower: how does it get through the winter?

Hardy to 5 °C: protect in harsh winters.

• Not hardy: it dies in frost and already suffers at around 5 °C. Treat it as an annual.
• Remove the dead stems after the first frost.
• Want to keep it? Collect seed or take cuttings in September and root them indoors.
• In a pot: bring it to a bright, warm room before the first night frost; flowering sometimes carries on for a while there.

Diseases and pests

• Weak or late flowering: Caused by a cool, dull summer, too much nitrogen or a pot that is too small. Put it in the warmest spot and feed sparingly.
• Aphids: On young shoots and buds. Spray off with water or let ladybirds do the work.
• Spider mites: In dry heat, especially in a pot. Water and mist the leaves.
• Slugs: Young plants are eaten in June. A collar round the plant helps, and collect slugs in the evening.
• Seeds do not germinate: Hard seed coat. Soak or nick them and keep them warm (20–25 °C).

Through the year

• January: Rest. Get seeds and materials ready.
• February: Prepare the support and the soil.
• March: Soak or nick the seeds and sow indoors.
• April: Sow. Put young plants in a bright, warm place.
• May: Harden off. Set up the support.
• June: Plant out after night frosts. Water and mulch.
• July: Water. Potash-rich feed every 2–3 weeks.
• August: First flowers in the evening. Remove spent flowers.
• September: Flowering. Water.
• October: Flowering until the first frost. Collect seed.
• November: Clear away dead plants.
• December: Rest. Store seed dry.

Edible and useful

Not edible. All parts of these morning glories are poisonous, especially the seeds: in purple morning glory and its relatives they contain alkaloids that cause nausea, vomiting, stomach ache and even hallucinations. That is why they are sometimes eaten on purpose as a ‘natural drug’, which is dangerous, and shop-bought seed is often treated with a fungicide as well. Keep seed packets out of reach of children and teenagers, do not leave ripe seed pods lying around, and keep dogs and cats away from the seeds. Never eat any of it. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Did you know?

• The flowers open quickly in the evening and are pollinated in the wild by hawk moths.
• The moonflower belongs to the same genus (Ipomoea) as the sweet potato and the morning glories.
• In the tropics it grows as a perennial vine that can climb several metres.