If you can leave them outdoors all spring-summer-fall (light frosts are no problem with these plants) with protection from rain, then you can easily get away with simple fluorescent lighting during the winter for most species, and Lithops may tolerate even less light since they are forming new leaves underneath their skins.

The key is to give them the strongest light possible during the spring and fall. Only during the hottest part of the summer, in a greenhouse, is some shade advisable. If they get fresh air outdoors then full blazing Ohio sun is perfect.

The exception here would be Conophytum, which should be shaded during the summer when most are completely dormant. They need sun and periodic watering when growth resumes in the late summer or fall.

I used to do this for many years with all sorts of different Mesembs and they grew and flowered perfectly under 40W fluorescents in the winter. Now I have an HID set-up for the winter, mainly for some of the other plants I have. The truth is that I have not noticed any difference with the Mesembs grown under winter HID vs. winter fluorescent lights other than maybe some Gibbaeum that never bloomed before. They seem to appreciate the higher light intensity of HID.

x

Forgot to add an important qualifier...for overwintering Mesembs indoors under less-than-ideal light, it should be as cold as possible. An unheated garage works well.

My garage stays in the 40's to 50's most of the winter. Any warmer and the plants will be more active and will need strong light.

Keeping mesembs at constant room temperature indoors during the winter is not good for them (they are much better off with nightly dips in temperature) and is a much more difficult feat to accomplish with artificial lighting.

x

Thanks. This sounds doable. My spare room is definitely on the cool side in the winter, fifties at best. Sitting in front of the window they'll drop a few degrees at night. I could even point a little fan at them at night.