How to Grow Crinum Plants in your Garden

Gardener's HQ Guide to Growing Crinum Lily, Cape Lily, Spider Lily, and Onion Plant

Crinum is a half hardy bulb, that is often grown as an annual by gardeners.

Crinum lilies bloom in the late summer. They have lily like flowers of red, pink, or white. These appear atop stems that are 45 to 90 cm (18 to 36 inches) in height.

Crinum powellii
Crinum powellii - Cape Lily by Drew Avery.

Common names for Crinum plant members include Cape lily, Bengal Lily, Crinum Lily, Spider Lily, and Swamp lily.

Crinum asiaticum
Crinum asiaticum – Giant Crinum Lily by Scott.Zona; creative commons.

Their beauty makes them ideal to grow as solitary plants.

Commonly Grown Crinum Species Photographs and Plant Identification

Crinum asiaticum

Crinum asiaticum
Crinum asiaticum (Giant Crinum Lily / Spider Lily / Poison bulb), photograph by Forest and Kim Starr; CC.

Crinum latifolium

Crinum latifolium
Crinum latifolium (Pink-striped Trumpet Lily / Wide-leaved Crinum Lily), picture by Dinesh Valke; CC.

Crinum americanum

Crinum americanum
Crinum americanum (Florida Swamp-lily / String Lily / Southern Swamp Crinum), picture by Rictor Norton & David Allen; CC.

Commonly Grown Crinum Hybrid

Crinum × Powellii

Crinum × powellii
Crinum × powellii (Swamp Lily Hybrid / Cape Lily Hybrid), photograph by eonora (Ellie) Enking; CC.

Crinum Growing and Care Guide

Common Names: Crinum Lily, Cape Lily, Spider Lily, Swamp Lily, Onion Plant, Sudarshana, Milk and Wine Lily, Natal Lily.
Life Cycle: Half hardy bulb commonly grown as a hardy annual by gardeners.
Height: 20 to 80 inches (50 to 200 cm). Large spread.
Native: Southern Africa, Australasia, Tropical Asia.

Growing Region: Zones 3 to 10. As a perennial in zones 8 to 10.
Flowers: Summer, early autumn.
Flower Details: Red, purple, white, pink. Lily-like. Clustered flowers. Umbel.
Foliage: Various shades of green. Strap shaped basal leaves. Leafless stems.

Sow Outside: Seeds: 1/4 inch (6mm) in autumn. Bulb: plant deep ~ 7 to 8 inches (17 to 20 cm) in late spring; temperature must not drop below 60°F (15°C). Spacing: 15 to 40 inches (38 to 100 cm).
Sow Inside: Sow using fresh seed in the autumn. Germination time: one to three weeks. Temperature 60 to 70°F (15 to 21°C) Transplant outdoors late spring; temperature must not drop below 60°F (15°C).

Requirements: Full sunlight. Good drainage. Humus rich soil. Moist soil. Supply a feed three times per annum. Many species can grow in swampy conditions and are therefore surprisingly tolerant of drought; it is still a good idea to water them in prolonged dry periods. Cut back after flowering; remove dead leaves. Can be grown as a perennial in warm areas but may still need a winter mulch. Treat as an annual in cooler areas by bringing bulbs indoors over the winter.

Family: Amaryllidaceae.
Miscellaneous: It will take at least four years for seed grown Crinum lilies to flower.

How to Grow Cape Lily, and other Crinum

Cape Lily and other lilies of the Crinum genus can be grown either from seed or bulbs.

If growing from bulb then they should be planted at a depth of 20 cm (8 inches) at the end of spring.

If you plan to grow Crinum plants from seed, then you should use fresh seed as soon as it is ripe, and sow at a depth of about 6 mm (1/4 inch).

The plants should be spaced between 45 cm (18 inches; small species) to 80 cm (32 inches; large species), and grown in a sunny area of the garden.

They like to grow in an humus rich moist soil that is well drained.

If you first plan to grow Cape (Crinum) lilies indoors, then fresh seed should also be used.

It should takes from one to three weeks to germinate lilies. Ideally grow at a temperature of 15 to 20 degrees centigrade (59 to 68°F).

Caring for Crinum Species

Members of the Crinum family are not the easiest to look after. They should be fertilised about three times a year.

The leaves and flowers should be cut off once they have died.

If you live in a very cold area, then the bulbs should be removed from the garden in the autumn and stored indoors in a cool place.

It may take as long as five years before you see flowers from your seed-grown Crinum lilies.

I hope that you enjoyed this guide on how to grow Crinum plants. You may also enjoy the following Gardener's HQ Amaryllidaceae growing guides: How to grow Allium schoenoprasum, Jersey Lily, and Amaryllis plants.