Calonyction Plant Growing & Care Guide for Gardeners

Article by Dean Ravenscroft, Ph.D. - Updated 20th Oct 2023

In this Gardener's HQ guide, we'll explore cultivating Calonyction plants in your garden, indoor spaces, and other settings.

Moonflower: Cultivation & Garden Use

Members of the Calonyction genus are climbing vines.

They have heart shaped leaves and trumpet shaped flowers of purple or white.

They flower at night from the middle of summer until the first frost of winter.

They are also known as Moonflower and Bona nox.

Moonflower by Nathan & Jenny

How to Grow Moonflower (Calonyction)

If planning to grow Calonyction outdoors then it is best to sow out the Moonflower seed after the last frost of spring; simply cover the seeds.

When growing them as seedlings indoors, then the process should be started about eight weeks before they are due to be planted out. The Calonyction seeds should be sown into peat pots. First soak the seeds overnight and chip them, then germinate at about 72°F (22°C) for about two weeks.

Seedlings should be planted out with a spacing of around 8 to 12 inches (20 to 30 cm) into a sunny or partially shaded area of the garden; the soil type is not important.

Moonflower bud by Titanium22

Caring for Calonyction

Climbing Calonyction vines will require a support such as a trellis that they can climb on. They should be frequently watered when growing.

Calonyction Growing Guide and Facts

Common Names: Moonflower, Bona nox.
Family: Convolvulaceae.
Life Cycle: Half hardy perennial usually grown as a half hardy annual by gardeners.
Height: 100 to 120 inches (250 to 300 cm).
Native: Tropics and Subtropics.
Growing Region: Zones 3 to 10.
Flowers: Mid-summer through to the first frost of winter.
Flower Details: White, purple. Trumpet shaped. Flowers open in the night time.
Foliage: Heart shaped.
Sow Outdoors: Cover seed. Following the last frost. Spacing 15 to 16 inches (38 to 40 cm).
Sow Indoors: Use Peat pots. Chip seeds. Soak overnight. Germination time: ten days to two weeks. Temperature 70 to 75°F (21 to 24°C), eight weeks before expected last frost. Transplant outdoors well after the the last frost, requires minimum temperature of 50°F (10°C).
Requirements: Full sunlight or partial shade. Average soils. Climbing vine so supply with a support such as a trellis. Regular watering whilst growing. Pinch tips.

Miscellaneous: Can also be classified into the genus Ipomoea (Morning glories) subgenus Quamoclit (Star Ipomoea).

Common Questions

How many members does the Calonyction genus have?

The Calonyction genus, often included in Ipomoea, includes a few species. The best known is Calonyction aculeatum (Moonflower).

Do members of Calonyction make a good garden or landscaping plant?

Yes, Calonyction, particularly the Moonflower, is a great climber for fences, trellises, or walls, with its large, night-blooming flowers.

Which Calonyction species are most frequently grown by gardeners?

The most frequently grown is Calonyction aculeatum (Moonflower), appreciated for its large, fragrant, white blooms that open at night.

Are members of the Calonyction plant genus fragrant?

Yes, the Moonflower (Calonyction aculeatum) has fragrant blooms that open in the evening and emit a sweet scent.

What is the perfect location to grow Calonyction?

Calonyction prefers a sunny location with well-drained soil. It's an excellent choice for vertical spaces in the garden.

Is Calonyction invasive in the USA?

Currently, Calonyction species are not considered invasive in the USA. They can spread in favorable conditions but are generally manageable.

How do I remove Calonyction plants from my garden?

To remove Calonyction, cut the vines back and dig up the roots. Monitor the area for regrowth as seeds can remain in the soil.

Summary

The Calonyction genus, part of the Convolvulaceae family, is native to tropical and subtropical regions of the Americas. The most recognized species, Calonyction aculeatum, also known as moonflower, is a vine recognized for its large, fragrant, night-blooming white flowers.

To cultivate Calonyction, plant them in a sunny to partially shaded location with well-drained soil. They can be grown from seeds sown in the spring. Regular watering is necessary. They're climbers and need support to grow. They're often used in trellises, pergolas, or fences, providing fragrant, night-time blooms that attract moths.

I hope that you enjoyed this guide on Calonyction. You may also enjoy the following Gardener's HQ growing guides: How to grow Ipomoea and Passiflora plants.