I would say it depends on where you live. Here in Phoenix, they are some of the toughest plants around, you often see them in busy street medians, being blasted with sun and exhaust fumes and blooming like crazy. So I know they tolerate (probably even like) a lot of heat. They also grow with little to no extra irrigation, so I'd say to be careful not to overwater them (although a baby might need a touch more). I'd also advise pretty poor soil with low organic matter that has excellent drainage to avoid root rot.

Congratulations on successful germination and good luck!

I sprinkled seeds in...probably August..(this years just matured ones) in raised beds where I have my cacti. I now have a fair number of little three leaf blade blades of "grass" (actually hesperaloe/red yucca). They seem to sprout easily and grow rather quickly for a succulent.
Come spring, it'll be time to work my hands around the spines and try to get them out (I had no idea I'd get that rapid a growth).