When to plant Zephytanthus Robustsa bulbs Common name Fairy Lilly
Certified GKH Gardening Expert
It will be best to plant these in Spring, after the soil warms up some. They are sensitive to freezing temperatures, so it is best to make sure that they are not exposed to them for long.
This article will help: https://www.gardeningknowhow.com/ornamental/bulbs/rain-lily/growing-rain-lilies.htm