I have several Crown Imperial Fritillaria. The last 3 springs, they came up with beautiful, healthy foliage but no flowers.
Wondering what I can do to encourage blooming next year.
Some have multiple stocks. Do i split the bulb now or when?
Thank you for contacting Toronto Master Gardeners about the frustration of your non-blooming Crown imperials (Fritillaria imperialis). You are not alone in this problem.
We can cull some useful information from the Royal Horticultural Society site:
Please note that the fertilizer suggestion is a British brand. Applying organic matter such as compost, leafmold and well rotted manure will both lighten and enrich clay soils. High potassium fertilizer is beneficial, and appears to be a nutrient that will promote blooming.
Potassium is the third key nutrient of commercial fertilizers. It helps strengthen plants’ abilities to resist disease and plays an important role in increasing crop yields and overall quality. Potassium also protects the plant when the weather is cold or dry, strengthening its root system and preventing wilt.
The Missouri Botanical Garden has a plant profile on Crown Imperial Fritillary:
http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a452 and offers some cultural information but, unfortunately, does not address the non-blooming characteristic.
We wish you well in coaxing your otherwise healthy Frit to bloom copiously.