Q.How Do I Get Bulbs That I Have Raised To Bloom?
I have propagated amaryllis from seeds 2.5 years ago. Several are now 20-24 cm in circumference. I brought them in for the winter, put them in pots with their long leaves attached. They are in a sunny window. My questions: how do I get them to bloom and are they too immature to bloom? Do I cut back the leaves? Do I make them go dormant?

Certified GKH Gardening Expert
Yes, they are likely to immature to flower. This can take anywhere from 3 to 5 years with proper care. This collection of articles will help you with the care of the plant:
https://www.gardeningknowhow.com/ornamental/bulbs/amaryllis-hippeastrum