I have been seeing a lot of conflicting information about the hardiness of crinum lilies. I assumed that they would be tender and need to overwintered indoors. I have come across some resources claiming that they can be left in the ground over winter and will return as perennials. If this is not the case, what is the best way to overwinter them? should they be planted in pots so that they can be moved indoors as houseplants over the winter or can they be lifted and stored like a dahlia tuber or elephant ear corm?
Thanks in advance!
Crinum lilies are native to warm areas of North America and Africa. Most grow well in warmer climate zones 7-11, for example Crinum asiaticum is hardy in zones 8-11 and C. americanum(southern swamp lily) grows in zones 9-11.
There are a few cold-hardy crinums, like Crinum x powellii and its cultivars C. moorei and C. longifolium (this last plant is also sometimes called C. bulbispermum or C. capense) – which may be hardy to zone 6. Depending on your location, your garden may be in a zone where the lilies would survive most winters. If you want to take a chance and try keeping the plants in your garden year-round, plant the bulbs in the spring after the last frost, deep in the soil (about 46 cm or 18 inches) and in a sunny spot. Water the bulbs well during the growing season, then after they flower, decrease watering so the leaves will die back. The area the bulbs are planted should be well-mulched in the winter, to increase the chances of survival.
However, rather than over-winter the bulbs outside, I’d suggest that you dig up the bulbs, transplant them into pots and move them indoors to a cool, well-lit area (10 degrees Celsius or 50 degrees Fahrenheit). Crinums like to be pot-bound, so choose a pot that is only a bit larger than the bulb. Water sparingly, and come spring, increase the temperature to 14 degrees Celsius (60 degrees Fahrenheit) and start watering enough so the soil remains moist. Start fertilizing them too. Move the plant outdoors once the danger of frost has passed. You could also choose to grow the plant entirely in a pot and just bring the pot indoors for the winter.
Finally, if you prefer, you can lift the bulbs from the ground after the first frost, cut off the leaves and store them as you would the tubers/corms you mention above — in a cool, dry spot, in a paper bag or a container filled with material like vermiculite, wood chips, sawdust, or coconut coir, to keep them from rotting. Plant the bulbs outdoors after the danger of frost has passed.
You have a few options to choose from – we’d love to hear how you decide to overwinter your lovely crinums and how they fare!
May 31 2021