How to Grow Crown Imperial Flowers (Fritillaria Imperialis)

By Matt Gibson

All About Crown Imperials

The Crown Imperial is a perennial spring flower that belongs to the Lily family. Formerly known as Persian Lily, Crown Imperials are striking, unique, beautiful, and off-putting, all at the same time. Growing anywhere from six inches to three feet, this Mediterranean, Middle Eastern and Asian native produces individual flowers or clusters of as many as ten flowers together, depending on the variety.

The odd-looking blooms appear from April to June, and have a crown of spiky green leaves on the top, with oval-shaped, pointed, vertical stripe-textured flower petals on the bottom of the bloom, which face downwards. Crown imperial’s flower petal colors can be red, orange, or yellow, depending on the variety.

The off-putting nature of these one-of-a-kind flowers, is due to the smell, which is described as a mixture between wet fur and garlic, musky or skunky. Whichever description you think fits the Crown Imperial odor the best, it is clear that most find it quite unpleasant at best. The smell of this exotic looking flower has upsides as well, as it is a natural deterrent against foraging animals, such as voles, and rodents.

Though Crown Imperials are not a common sight in many North American gardens, they are hardy to USDA zones five through nine, so they can definitely be grown in North America, and depending on the climate you live in, can be added to your flower garden for a touch of exotic flare (as long as you don’t have a delicate sense of smell.

Varieties of Crown Imperial

There are seven varieties which are considered the main types of the Crown Imperial flower, each displaying their own unique features and general characteristics. Below, we listed off each main variety, and gave a brief description of each.

Aurora – This lovely cultivar grows two to three feet high and is hardy to USDA zones 5a through 8b. The aurora variety displays bright golden-orange bell-shaped flower heads with pendant-shaped petals topped with a small crown of small, medium-green, glossy, lance-shaped leaves, all of which sits atop an upright stem. Blooming from mid to late spring, the aurora Crown Imperial is well-suited to both beds and borders in just about any type of garden. In addition to deterring voles and rodents, the aurora cultivar also drives away deer and rabbits, not just from its odor, but from its large nectar drops, which larger foraging animals tend to dislike.

Bach, Beethoven, and Brahms – These three cultivars are so similar, they could easily be mistaken for each other, even by an expert horticulturist. One of the few distinguishable differences between the three plants is the color of their flower petals, all of which are pretty similar to each other. Bach’s petals are a bright orange-red that is slightly more red than orange, while Beethoven’s petals are a more dusky, or pale orange-red that is slightly more orange than red, and Brahms’s petals are a salmon-pinkish-orange. Each of the three have pendant-shaped petals and bell-shaped blooms, and each variety’s petals turn purple at the base.

All three of these cultivars are dwarf-sized Crown Imperials, which grow no higher than two feet at full maturity. All three bloom from mid summer to late spring, and have flower heads which are grouped together in groups of six to 12 bulbs. Each plant has very similar growing requirements, needing moist but very well-draining soil and full sun to partial shade. The Brahms variety has one unique trait that is different from the other two cultivars, or any other Crown Imperial cultivar, which is that it is lacking the pungent, musky odor for which Crown Imperials are known for. The Brahms variety, due to its odorless blooms, is susceptible to rabbit and deer foraging, and does not attract bees. Bach and Beethoven, on the other hand, both share the common Crown Imperial scent, are rabbit and deer resistant, and produce large drops of nectar which attracts bees.

Maxima Lutea – The maxima lutea Crown Imperial stands out amongst the other six main varieties as the sole yellow-bloomed flower, whereas each of the other six imperial cultivars are various shades of orange, some with a reddish tint, some with a salmon pink tint, and some which fade to purple at their base. Maxima lutea is the tallest variety, clocking in at five feet tall. With its massive size and striking color, this variety is one of the most incredible flowers you can find, and certainly the most ornate and mesmerizing variety of Crown Imperials. However, the maxima lutea has one significant drawback. Unlike most Crown Imperial varieties, which have a pungent scent that repels rabbits and deer, the maxima lutea smells like a wild animal, which ironically attracts rabbits and deer.

Rubra Maxima – The rubra maxima is one of the largest varieties of Crown Imperial. At around four feet tall, the burnt-orange and flushed red flowers are large and intricately designed. If inspected from a close range, you can see that each flower possesses nectaries that are shaped like eyes and edged with a decorative pattern. The veined foliage and ridged flower petals add to the detailed artistry of the rubra maxima Crown Imperial. Taking in the majesty of this variety up close, it’s easy to understand why it is one of the most beloved varieties, and has been regularly cultivated since its discovery in 1590.

The Premier – Growing two to three feet high, the premier variety of Crown Imperial is most certainly a show stopper. Not only does it have the Crown Imperial’s signature, grass-like crown, its flower petal colors are truly unique and stunning. The bright-orange petals are streaked with purple, which really stands out when provided with a loud orange backdrop. Premier Crown Imperials will bloom year after year if given its preferred growing conditions. This cultivar needs full sunlight for its best growth, but will adjust to partial shade conditions. Allow soil to dry out between waterings, as this cultivar is especially prone to rotting.

Growing Conditions for Crown Imperial

Hardy to USDA zones four through nine, the Crown Imperial can also be treated as an annual in colder climates. Though it can survive indoors as a houseplant, the pungent odor of most varieties probably keeps that possibility from occurring often. Crown imperials need full sun locations in order to form full-size flowers. They will survive in partial shade, but the blooms will be smaller, and duller.

Crown imperials need moist soil but require a very well-draining medium. Provide a medium amount of moisture, watering lightly on a regular basis instead of deeply on occasion. Add a two to three inch layer of organic mulch to deter weeds and improve moisture retention. Amend hard soils or clay based soils with sand or fine gravel to increase drainage.

How to Plant Crown Imperial

Plant Crown Imperial bulbs in the fall, around the same time as daffodils and tulips to get mid-spring blooms. Sow Crown Imperial bulbs deep into the soil, ten to 11 inches beneath the surface of the soil. Planting the bulbs at this depth allows the plants to draw water from deep within the lower layers of soil. Space plants about eight to 12 inches apart from one another and apart from any other plant.

Crown imperial bulbs have a tendency to dry out very quickly, so be sure to plant your bulbs as soon as you get them home from the nursery, or as soon as they arrive in the mail. Crown imperial bulbs have a divot on the top side. Plant your bulbs tilted at an angle so that the divot doesn’t fill with water. If the bulb is allowed to collect water, it will quickly start to rot.

Care for Crown Imperial

Established Crown Imperial plants don’t require much care and attention. Water once per day early in the morning before the sun gets too hot, or late in the afternoon, once the temperature begins to cool down. If you notice that the water you provide is evaporating too quickly, use additional mulch so that the plant has an opportunity to soak up the moisture for longer periods of time.

Feed once during the spring with an organic or mineral-based fertilizer. Side dress the soil with semi-mature compost in the spring as well. Feed your imperials once more in the late summer by diluting a liquid fertilizer in the water you provide for the plant. Do not trim back the foliage until it has withered away entirely, allowing the plant to absorb plenty of nutrients for the next growing cycle before cutting it back.

If you notice your plant beginning to lose vigor, feel free to fertilize the ground directly, as Crown Imperials need very rich soil to thrive. Cut the leaves down short just before wintertime and add a layer of dried leaf mulch around the base of the plants to protect them from the cold. When pruning, remove all faded inflorescent entirely

How to Propagate Crown Imperial

Mature Crown Imperial plants do not appreciate having their roots disturbed, but they can be propagated through division. Once the leaves have ripened, dig and split offsets from their parent bulbs during the summer.

Smaller bulbs should be potted up quickly and kept in a bright area that provides protection from heavy winds for the first year of growth. Large Crown Imperial bulbs can be moved to their permanent homes immediately.

Propagation via seed requires quite a bit of patience. Seeds require at least three weeks of cold stratification before starting the germination process. Sow seeds into flats when they ripen and cover very lightly with a fine starter soil or potting soil before moving to a cold frame or plastic wrapping it in plastic and digging up a safe spot for it in the garden.

Crown Imperial seeds will germinate during the springtime, but keep your seedlings in their flats for the first year before moving them out into the garden during autumn.

Garden Pests and Diseases of Crown Imperial

Though Crown Imperial is resistant to just about every common plant disease, root rot can be a serious issue for the flower. Plant bulbs tilted at an angle, avoid overwatering, and provide a well-draining soil to prevent rot issues. Space plants out at least nine to 12 inches to give bulbs adequate air circulation, which will minimize the chances of rot, as well as fungus, rust, and leaf spot issues.

Scarlet lily beetles are also commonly found on Crown Imperials. The infestation of tiny red beetles starts in the spring around the start of April. The beetles eat holes into the leaves of Crown Imperials. Scarlet lily beetles can be tough to control, as insecticides can’t kill the beetles without also harming the plants in the process.

Alternative treatment options include picking the insects off by hand, setting up glue traps around the affected plants, and releasing predator insects that are natural enemies to the scarlet lily beetle, such as worms, insect eaters, birds, hedgehogs, and the ichneumon fly. If the beetles are a problem every year, throw out all infected plants.

Crown Imperial flowers are unique, exotic-looking, and rare in western gardens, which makes them all the more intriguing to grow in your own garden beds. The pungent odor aside, there is nothing else negative to say about these odd-looking flowers. Plant them in containers or directly into your garden beds, either individually, a few at a time, or in masses. Either way you choose, Crown Imperial is well suited to the task.

Toxicity Warning

All parts of this plant are poisonous to humans and pets if ingested. If you are growing Crown Imperials in your garden, keep small children and pets away from these plants, as they are highly toxic, and can cause cardiac problems if ingested. If any parts of the Crown Imperial plant are ingested, seek immediate medical attention.