Your plan sounds good. Here I have the greenhouses in winter and shadehouses in spring, summer and fall for the broms. Humidity here is 90% a lot of the year. I raise hundreds of seedlings also and have no problems with damping off.

I don't know why I've had damping off issues this past year---I can't seem to get rid of it. What zone are you in? If I move broms outside for the summer, at what temp should I move them back in the greenhouse?

The temps will depend on what you are growing but certainly any time frost is threatning. My zone is 9

Poetmama,

Your conditions are quite similar to mine. I aim to keep winter night-time temps in the mid 50s, although the greenhouse will dip into the 40s on those brutally cold nights. I try to maintain 63-65F during the day. My broms languish during the winter, but that's mostly because of all the "lake effect" cloudiness that we deal with here. On the rare sunny days that we get during the winter, temps will easily reach a welcome 80-90F in the greenhouse! Depending where in Illinois you live, you may get more winter sun than I get here.

During the summer, I move my broms outdoors (starting mid May) and place them under 40% shade. Cold sensitive species and hybrids get moved back into the greenhouse when night time temps are getting down to about 40F (usually 3rd or 4th week in September). Hardier types, such as many of the Tillandsias and Neoregelias, may remain outdoors until frost threatens (typically mid-October here). A couple of hardy Tillandsias remained outside here until December 1. They seemed quite unfazed by several nights in the mid 20s!

I can't comment too much on your "damping off" problem. Good air circulation is alleged to be a remedy. In any case, your bromeliads will also beneifit from a fan or two in the greenhouse.

Paul