Fritillaria imperialis

crown imperial

At a Glance

TypeBulb
HabitUpright
FoliageDeciduous
Height30-48 inches (75-120 cm)
Width10-12 inches (25-30 cm)
Maturity1 years

Growing Zones

USDA Hardiness Zones

5 - 8
These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →
Frost Tolerancehardy

Overview

Fritillaria imperialis is a bulbous perennial in the Liliaceae family, growing 30–48 inches (75–120 cm) tall from a large, fleshy bulb 4–6 inches (10–15 cm) in diameter with a distinctive hollow centre. The stout, erect stem emerges in early spring, clothed in whorls of glossy, lance-shaped leaves 4–6 inches (10–15 cm) long along the lower two-thirds. The inflorescence is a terminal umbel of 3–8 large, pendant, bell-shaped flowers 2–2.5 inches (5–6 cm) long, topped by a crown of erect, leaf-like bracts — the "crown" that gives the plant its common name. Flower colour ranges from orange and burnt orange through red and yellow depending on cultivar. Each tepal bears a large, white, glistening nectary drop at its base that does not fall even when the flower is inverted — a feature that has fascinated botanists since the 16th century. The entire plant has a strong, musky, fox-like odour (described as skunky by some) emanating from the bulb and lower stem, attributed to isopentyl methyl sulfide. This scent is reputed to deter rodents, moles, and deer, though evidence is anecdotal. Cultivated in European gardens since at least 1576, when Clusius received bulbs from Constantinople. The bulb is fragile — unlike most bulbs, it has no protective tunic and dries out rapidly if stored improperly. Plant immediately upon receipt. All parts are toxic, containing steroidal alkaloids (imperialine).

Native Range

Fritillaria imperialis is native to a wide arc across western and central Asia, from southeastern Turkey through Iraq, Iran, Afghanistan, and into Pakistan and the western Himalayas. It grows on rocky mountain slopes, in scrub, and in subalpine meadows at elevations of 3,000–9,000 feet (900–2,700 m).

Suggested Uses

Planted as a specimen in spring borders, spaced 10–12 inches (25–30 cm) apart in groups of 3–5 for visual impact. The tall stem and crown-shaped inflorescence create a focal point rising above lower spring perennials and tulips. Effective in cottage garden borders and in formal spring plantings. The musky scent is noticeable at close range — site accordingly.

How to Identify

Identified by the tall, stout stem with whorled glossy leaves, terminal umbel of large pendant bell-shaped flowers, and the distinctive crown of erect bracts above the flowers. Distinguished from all other Fritillaria species by the much larger size, umbellate inflorescence, and crown of bracts. The strong musky odour of the bulb and plant is also diagnostic. The glistening nectar drops at the tepal bases are unique in the genus.

Appearance

Size & Dimensions

Height2'6" - 4'
Width/Spread10" - 1'

Reaches mature size in approximately 1 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks
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Flowers open from mid-April through early May in the Pacific Northwest, lasting 2–3 weeks. Each umbel of 3–8 flowers opens nearly simultaneously. Pollinated by large bees and wasps attracted to the copious nectar. After flowering, the stem remains erect as seed capsules develop, then the entire above-ground structure yellows and collapses by late June. Bulbs enter dormancy in summer.

Detailed Descriptions

Flower Description

Orange, red, or yellow depending on cultivar

Foliage Description

Glossy bright green

Growing Conditions

Sun Requirements

Requires 5-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.5 - 7.5(Neutral)
357912
Soil Types
Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1 year from planting to bloom

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant bulbs in September–October, immediately upon receipt — the tunicate-free bulb desiccates rapidly in storage. Plant 6–8 inches (15–20 cm) deep on its side (tilted at 45°) to prevent water collecting in the hollow centre, which causes rot. Space 10–12 inches (25–30 cm) apart. Site in full sun to light shade in fertile, well-drained soil with a pH of 6.5–7.5. Avoid heavy clay. Add a handful of coarse grit below each bulb to improve drainage. Water during the autumn and spring growing period; allow the soil to dry during summer dormancy. Feed with a potassium-rich fertiliser in early spring as shoots emerge, and again after flowering. Do not disturb established clumps — the species resents transplanting and may skip a year of flowering after being moved.

Pruning

Remove the seed capsule after flowering to redirect energy to the bulb, unless seed is desired. Do not remove the stem and leaves until they have yellowed completely (typically late June) — the foliage photosynthesises to recharge the bulb. Cut the dead stem at ground level.

Pruning Schedule

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summer

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 5 gallons

⚠️ Toxicity Warning

Toxic to pets and humans