Crown imperial 'William Rex' Fritillaria imperialis 'William Rex'

Water

The Crown Imperial (Fritillaria imperialis 'William Rex') should be watered deeply to ensure the soil is moist but not waterlogged, typically about 1 inch of water per week. During the growing season, water the plant when the top inch of soil feels dry to the touch, which may result in watering approximately every 7-10 days, depending on weather conditions. It's important to reduce watering after the foliage begins to die back post-flowering and during the dormant period to prevent bulb rot. Provide the plant with around half a gallon of water for each watering session to ensure the soil is adequately moistened.

Light

Crown Imperials prefer full sunlight to thrive and produce the best blooms, requiring at least 6 hours of direct sunlight daily. They can tolerate partial shade but may not flower as prolifically. Place the Crown Imperial where it will receive unfiltered sunlight throughout the day for optimal growth and flowering.

Temperature

Crown Imperials are best suited for cooler climates and can endure winter temperatures as low as 10°F but not below -10°F. Ideally, they prefer daytime temperatures between 50°F and 70°F. It is critical to protect them from extreme heat, as temperatures consistently above 80°F could be detrimental to their growth and health.

Pruning

Prune Crown Imperials by deadheading spent flowers shortly after they fade to conserve plant energy. Cut back the foliage only after it has turned yellow and begun to die down on its own, usually in late spring or early summer. Pruning is typically not required at other times unless removing damaged or diseased foliage.

Cleaning

As needed

Soil

Crown Imperial Fritillaria prefers well-draining, fertile soil with abundant organic matter. Aim for a soil pH between 6.0 and 7.0. A mix of loam, sand, and compost would serve as an ideal soil composition for this plant to ensure good drainage and nutrient availability.

Repotting

Crown Imperial Fritillarias are generally repotted every few years or when they outgrow their current container. It's best to repot after the foliage has died back, in late summer or early fall, as this plant is a spring bloomer.

Humidity & Misting

Crown Imperial Fritillaria is tolerant of a range of humidity levels but does not require high humidity. Average room humidity is usually sufficient for this plant when grown indoors.

Suitable locations

• Indoor

  Ensure bright light, cool temperatures, and well-draining soil.

• Outdoor

  Plant in full sun to part shade, well-draining soil, springtime.

• Hardiness zone

  5-9 USDA

Life cycle

Crown Imperial 'William Rex' begins its life as a bulb, which is typically planted in the fall to establish roots before the winter. In spring, the bulb sends up a stout stem, which bears lance-shaped, glossy leaves and a prominent, crown-like arrangement of bell-shaped flowers, ranging from red to yellow, blooming from late March to May. After flowering, the plant goes into a period of photosynthesis and energy storage, replenishing the bulb for the next season. As the temperatures warm up in late spring or early summer, the foliage dies back and the plant enters a dormancy phase during the hot summer months. In this resting state, the bulb survives underground until the following spring when the cycle begins anew with the emergence of new growth. With each annual cycle, the bulb can grow larger and may eventually produce offsets, or daughter bulbs, which can be separated and planted to propagate new plants.

Propogation

• Propogation time

  Spring

• Propogation: Fritillaria imperialis 'William Rex', commonly known as Crown Imperial, is typically propagated by bulb division. The best time to propagate this plant is in the autumn, after the foliage has died back and the plant is dormant. The large bulbs of the Crown Imperial can be carefully dug up and the offsets, which are smaller bulbs that grow attached to the mother bulb, can be separated. Each offset must have some roots attached to ensure successful growth. These offsets can then be planted immediately at a depth of approximately 6 inches (about 15 centimeters) in well-draining soil with the pointed end facing upwards. It is important to space them about 12 inches (30 centimeters) apart to give them enough room to grow. With proper care, these offsets will develop into mature flowering plants in a few years.