Lilium superbum, commonly known as the Turk's Cap Lily or American Turk's Cap Lily, is a spectacular North American species producing tall stems topped with numerous nodding, strongly recurved orange flowers. Each bloom is heavily spotted with dark maroon and develops richer red-orange tones towards the tips as it matures.

A mature plant is an impressive sight. Established bulbs can produce substantial racemes of flowers on stems reaching 180-240cm in favourable conditions, making Lilium superbum one of the tallest and most dramatic species lilies for the garden. Unlike many lilies that prefer relatively dry conditions, this species is naturally associated with moist meadows, woodland edges and damp ground, making it especially useful for fertile areas that remain reasonably moisture-retentive during summer.

• Botanical name: Lilium superbum
• Common names: Turk's Cap Lily, American Turk's Cap Lily, Swamp Lily
• Plant type: Bulbous perennial
• Flower colour: Orange to red-orange with maroon spotting
• Flowering time: July-August
• Height: Approximately 150-240cm when established
• Spread: Approximately 30-45cm
• Position: Full sun or partial shade
• Soil: Fertile, humus-rich, moisture-retentive but well-drained soil
• Ideal for: Moist borders, woodland gardens, naturalistic planting and cut flowers

About Lilium superbum

Native to eastern North America, Lilium superbum is a vigorous species lily with a very different character from the large modern Oriental hybrids. Tall green stems, often attractively mottled with purple, carry whorls of narrow leaves before branching towards the top into an impressive flowering head.

The flowers hang downwards before their tepals sweep dramatically backwards, producing the characteristic Turk's-cap shape. Colour begins with greenish tones around the throat before changing through yellow-orange and fiery orange to deeper red towards the recurved tips. Numerous dark maroon spots cover the inner surface of the flowers.

Well-established plants can produce an extraordinary number of blooms, sometimes several dozen on a particularly strong stem.

Where to Grow Turk's Cap Lilies

Lilium superbum appreciates more moisture than many commonly grown lilies. Choose fertile, humus-rich soil that remains reasonably moist during spring and summer but is not permanently waterlogged.

A position in sun or partial shade is suitable. It is particularly effective in naturalistic borders, moist woodland edges and amongst moisture-loving perennials, where its towering flowering stems can rise above surrounding foliage.

Because plants can eventually exceed 2m in height, some shelter from strong winds is beneficial.

How to Plant Lilium superbum Bulbs

Plant the bulbs promptly after arrival, as lily bulbs can lose moisture if left exposed for too long. Set them approximately 15cm deep with the growing point facing upwards.

Space bulbs around 25-30cm apart if planting several together. Incorporate plenty of well-rotted organic matter into poorer soils to improve fertility and moisture retention.

A mulch of garden compost or leaf mould in spring will help conserve soil moisture while gradually feeding the plants.

Height and Spread

Lilium superbum is a genuinely tall species. Plants commonly reach around 150-200cm, while established bulbs in particularly favourable conditions may approach 240cm (8ft). Allow an approximate spread of 30-45cm per mature plant.

After Flowering

Once flowering has finished, remove the developing seed heads if seed is not required, but leave the stems and foliage untouched. The leaves continue to feed the bulb and should be allowed to yellow and die back naturally before the old stems are removed.

Where conditions suit it, Lilium superbum can remain undisturbed for many years and will generally become increasingly impressive as the bulbs mature.

Why Grow Lilium superbum?

• Spectacular strongly recurved Turk's-cap flowers
• Vivid orange and red colouring
• Heavy decorative maroon spotting
• Can produce numerous flowers on mature stems
• Impressive height of up to 2m or more
• Spread of approximately 30-45cm
• Excellent for moist and humus-rich borders
• Ideal for naturalistic and woodland-style planting
• A distinctive North American species lily

Frequently Asked Questions

How tall does Lilium superbum grow?
Plants usually reach around 150-200cm, although mature bulbs in ideal conditions can grow to approximately 240cm tall.

What is the spread of Lilium superbum?
Allow approximately 30-45cm around each established plant.

When does the Turk's Cap Lily flower?
It normally flowers during July and August, providing a dramatic mid- to late-summer display.

What colour are the flowers?
The blooms are bright orange to red-orange, becoming greenish towards the throat and heavily spotted with dark maroon.

Does Lilium superbum like damp soil?
Yes. This species naturally occurs in moist habitats and prefers fertile soil that retains moisture during its growing season. Good drainage is still important, particularly during winter.

Can Lilium superbum grow in partial shade?
Yes. It grows well in sun or partial shade and is particularly suitable for bright woodland edges and naturalistic planting.

Does it come back every year?
Yes. Lilium superbum is a perennial bulb and can remain in the ground permanently where the soil and drainage are suitable.

With its towering stems, fiery orange-red flowers and dramatically recurved spotted petals, Lilium superbum is an outstanding species lily for gardeners looking for height, character and a more naturalistic alternative to modern hybrid lilies.