Bulb · Liliaceae
Crown Imperial
Fritillaria imperialis
Tall spring bulbs topped with nodding bells and a bold skunky scent that sends voles packing.
Full sun
Every 7–14 days
USDA 5–8
3–4 ft · 0.9–1.2 m
Overview
Crown imperial rises well above most other spring bulbs, pushing up a sturdy stem 3 to 4 feet (91 to 122 cm) tall that is capped by a circle of nodding bells and a leafy tuft that looks a little like a pineapple. A member of the lily family, it comes from the rocky slopes of the Middle East and the Himalayas. Give it a home toward the back of a border where that early color can really do its work, and don't fret about getting the placement perfect.
Every bit of the plant puts out a strong skunky, musky smell, and here is the happy surprise: that is a gift, not a drawback. The scent keeps voles, mice, and other diggers from bothering the bulbs. It does mean you'll be glad to set it a step away from a path or door where you would otherwise brush past it each day.
This bulb is happiest when you simply let it be. It settles in slowly, flowers for many years once it feels at home, and dislikes being dug up, so choose the spot thoughtfully and trust your choice. Sort out the drainage and lay the bulb properly, and crown imperial becomes one of those easygoing plants that quietly comes back every spring.
Care
The short version: give it full sun and deep, rich, sharply drained soil. Keep it evenly moist while it grows in spring, let it dry out once the leaves fade, and simply leave the bulb in the ground.
Light
Crown imperial blooms most freely in full sun, though it will happily take a little afternoon shade where spring warms up fast. Give it too much shade, though, and you'll get tall, leaning stems with fewer bells to show for it.
Water
Keep the soil evenly moist as it grows through spring, reaching for the watering can every 7 to 14 days whenever rain runs short. Once the leaves fade in early summer, stop and let the bulb dry off, because standing wet soil is what rots the bulb.
Soil
Plant it in deep, rich, well-drained loam or clay loam with lots of organic matter mixed through. A pH of 6.0 to 7.5 suits it nicely, and sharp drainage counts above all else, since sitting water will do the bulb in.
Temperature
This is a hardy, cold-loving bulb that copes with -20°F to 75°F (-29°C to 24°C). It actually needs a winter chill to flower and shrugs off hard frost, so it is the summer heat and humidity, not the cold, that it minds.
Humidity
Regular outdoor air suits it fine, so there is no target number to chase. What matters more is moving air around the leaves, since crowded, damp foliage is what invites leaf spot and rust.
Feeding
Mix in a balanced bulb fertilizer or compost when you plant in fall, then feed again in early spring as the shoots break through. That seasonal helping is all it asks to flower well, so there is no need to overdo it.
Pruning
Snip off the finished flower stem once blooming ends, but let the leaves stand until they yellow and die back on their own. Those fading leaves are quietly feeding next year's flower back down into the bulb.
Repotting
Crown imperial truly prefers to be left in peace. Only lift and divide a clump every 3 to 5 years, and even then only if flowering starts to taper off or the bulbs grow crowded.
Size & spacing
Each stem climbs 3 to 4 feet (91 to 122 cm) tall and spreads roughly 12 to 18 inches (30 to 46 cm) across. Set the bulbs 9 to 12 inches apart so the clumps have breathing room and air can pass between them.
When to plant
Crown imperial keeps time by the bulb's own inner clock, and it forgives a loose schedule. Get the bulbs in during fall while the soil still turns easily, watch the shoots come up early, and savor the bells through mid to late spring before the whole plant settles down and rests underground for summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant bulbs in fall, 6 inches deep and 9-12 inches apart, positioned sideways to prevent water collecting in the stem cavity
- Harvest: Mid to late spring, April to June
Hardiness
USDA hardiness zones: 5–8
Temperature: down to -29°C
Troubleshooting
Most crown imperial hiccups begin down at the bulb or turn up on the leaves once growth is underway, and the good news is that spotting them early gives you room to act before things spread. Find what matches your plant below, then step in gently while your help still counts.
A bulb gone soft and a plant that never shows up
Take heart, because this is a common stumble and one you can recover from. What you are seeing is bulb rot, and it usually comes down to ground that stayed too wet or a bulb set upright, which lets water settle into the stem cavity. Ease a suspect bulb out and you may find brown, smelly tissue near the central hole. Toss anything far gone, tuck the firm bulbs back in on their side in soil that drains sharply, and mix in some grit to keep water moving through.
Fix:
- Discard severely rotted bulbs
- Replant healthy bulbs on their side in sharply drained, raised soil
- Improve drainage with grit or organic matter
Streaky, mottled leaves and a plant losing its spark
This one is harder news, but you can still protect the rest of your garden. Blotchy light-and-dark patterning that stays put no matter how you rub it usually means mosaic virus, often brought in by aphids. Sadly there is no fixing a plant once it has this, so lift and destroy the sick ones, stay on top of sap-feeding insects, and give your tools a quick clean between plants so nothing hitches a ride.
Fix:
- Remove and destroy infected plants to limit spread
- Control aphid vectors
- Disinfect tools between plants
Spots and rusty bumps showing up on the leaves
No need to worry, since these fungal issues, leaf spot and rust, are easy to manage once you notice them. They settle in when leaves stay damp and packed too closely together. Turn a leaf over and look for raised, rust-colored bumps underneath, then simply pluck off the marked ones. Open up a little more space between plants and try to keep water off the foliage, and you will see the spread slow right down.
Fix:
- Remove and destroy affected foliage
- Improve air circulation
- Avoid overhead watering
Toxicity
This is one to respect. All of crown imperial holds steroidal alkaloids, and the bulb carries the most, packed with imperialine and related compounds. Swallowing it brings vomiting and stomach pain, and a large amount can throw off the heartbeat, so keep the bulbs away from pets, livestock, and children. That strong skunky smell puts most animals off, though you should not count on it alone.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that chews a bulb tends to drool first, then bring it back up with diarrhea close behind. Should it swallow a larger dose of the alkaloids, expect it to turn weak and sluggish.
Dogs Toxic
Dogs have a knack for digging up the bulbs, and a mouthful brings drooling, a queasy stomach, and vomiting. A bigger helping can even knock the heartbeat off its steady rhythm.
Horses Toxic
The bulb's alkaloids upset a horse's digestion and, taken in quantity, can unsettle the heart. It is safest to keep crown imperial far from grazing ground.
Rabbits Toxic
This is not something a rabbit should nibble. Even a little bulb or leaf can leave it drooling and uninterested in food, with diarrhea soon after.
Livestock Toxic
Cattle, goats, and sheep that reach the bulbs may end up with digestive upset, and enough of the alkaloids can bring on heart-rhythm trouble.
Birds Toxic
Count the bulbs and leaves as off-limits for birds, since the alkaloids that harm mammals can also make a pecking bird ill.
People Caution
No part of this plant is food. A swallowed fresh bulb brings vomiting and stomach pain, and a large amount of the alkaloids can reach the heart, so keep bulbs well out of a child's reach.
All parts of the plant have a strong skunky or musky odor, which usually discourages tasting; wash hands after handling bulbs.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
A handful of named crown imperials turn up most often, plus one much smaller relative that is worth getting to know. These are the ones to keep an eye out for.
Rubra
The familiar crown imperial you picture, wearing a crown of nodding bells in burnt orange to deep vermilion red.
Lutea
A yellow-flowering version that brightens the spring border with clear gold bells in place of orange.
Fritillaria meleagris (Checkered Lily)
A far smaller relative at 8 to 12 inches, dangling nodding bells checkered in purple, red-brown, and white much like a guinea hen's feathers.
How to propagate
Crown imperial takes its time multiplying, and the slow, patient methods reward you far more than seed does. Here is how each one works and roughly how long you'll wait.
Offsets & pupsModerate
Lift and separate offset bulblets in late summer to fall when foliage has died back · 1-3 years to reach flowering size
Your most reliable route to more plants is to dig up the clump once the leaves have faded in late summer or fall and gently ease away the little offset bulbs. Treat them tenderly, as they bruise readily and a nicked bulb tends to rot, and give it 1 to 3 years before an offset grows big enough to flower. That strong skunky, musky smell on the bulbs and leaves is just part of the deal.
DivisionModerate
Divide established clumps in fall every few years · 1-2 seasons
Once a clump grows crowded, lift it in fall and split it apart every few years, which is a friendly, forgiving job. Get each piece back in the ground straight away at the right depth, laid on its side so water cannot puddle in the bulb, and it usually returns to flowering within 1 to 2 seasons.
SeedDemanding
Sow fresh seed in fall · Slow; 4-6 years or more from seed to first bloom
Starting from seed asks for real patience, so save it for when you feel adventurous. Sow fresh seed in fall and you are looking at 4 to 6 years, sometimes more, before that first bloom, which is exactly why most gardeners happily lean on offsets or division instead.
Myths
You can eat crown imperial bulbs because folks claim cooking makes them safe.
Please don't try it. Fresh bulbs are poisonous and carry steroidal alkaloids, even if extension sources call the poison severity low. This is simply not a food plant, so handle the bulbs as toxic and keep them away from pets and children.