AWS is, of course an automatic weather station. My son has a Stanhopea nigroviolacea growing in a hanging basket under a very open trellis out in the weather. It flowers without fail mid summer. So it is not a glasshouse plant here while Vandas are. I keep getting back to the mythical set of conditions where you can grow lots of things in the one enclosure. What are they? Certainly they were not the ones where they were trying to grow Vandas at Kew when i visited in 1996. Those Vandas looked stressed to my eye. Perhaps they have them growing better now. I keep going to Botanic Gardens in the hope of seeing some great orchids. Mostly to be sadly disappointed. Though i did see some great terrestrial orchids growing in a cold frame at Christchuch New Zealand. Mostly species from Europe. Just beautiful. My Daughter in Law photographed some wonderful orchids in Montreal so some places get it right, but i'm afraid most fall for the tropical myth, so you have a glasshouse set for tropical lowland conditions where they try and grow non tropical lowland orchids. As for 90F with 90% humidity. That sounds positively awful. When you walk into your glasshouse during the day, it should be pleasantly warm with moderate humidity. Those humidity readings should be taken at various times during the day and some taken during the night. For what it is worth, I have just looked at the max/min thermometer at head height in the glasshouse where i mostly grow Tolumnia Hybrids and Cattleyas. I haven't reset it for months and we are sliding into winter. It says Max 46C Min 10C. Strange that there are a few orchids growing at that level and thriving. Way back in 1972 when i got my first glasshouse, i tried to maintain 55F during winter nights and didn't have all that much success and was rather amazed that out of room Cattleyas did better when put in an unheated shadehouse where sometimes it gets down to 5C, but after such a cold night the days are always sunny. . Since then have never worried about the minimums in my glasshouse all that much. Just set the heating to warm up the glasshouse during winter days and forgot about tropical lowland and mist forest orchids.

gwoods: The nurseries have no idea what's going on in your greenhouse and probably don't even know what it takes to chill various fruits. Sure it's no problem outside in ID so no one gives it a thought. But outside and in a greenhouse are way different. You need a ~1,200 hrs in the 30s and 40s to chill most apple, peach, and apricot. This year I went 69 straight days between 37 and 57 to get 1270 chill hrs. But my nights are warm enough, ave 30F, that I can heat to ~40F so as to maximize chilling all night long. I think the right approach in your climate is to just heat to avoid damaging temperatures in mid winter. I'd set a goal of maintaining 0F as a minimum. If it goes a little colder that's OK. But all those hrs between zero and 32F give exactly zero chilling hrs. So you need to maintain 30s and 40s on sunny winter days. That will give some chilling in mid winter. In fall and spring you might need to follow my example and heat to 40F to maximize chilling at night. Then hold daytime below 60F because above 60F is actually negative chilling. The meter is running backwards and you're losing chilling. Below 32 at night and 60+ by day is near zero chilling, could even be negative chilling. There are lots of ways to fail growing fruit in a greenhouse. Pay attention to chilling because that's one way to fail. This post was edited by fruitnut on Sun, Feb 9, 14 at 17:27

Swamp coolers can generally get 2/3rds of the way to the wet bulb temp. I expect your dew point is something like 60F, so you might get down to 80F. As you have cold air at night you might instead keep lots of water in your greenhouse and cool the water at night (perhaps by draining the greenhouse roof back into your water storage, and spraying water over the roof at night. something like this: http://www.pnl.gov/TechReview/whitecap/whitecap.html They claim 25 ton-hours per 1,000 ft2 of roof spray area. During the day you could absorb the heat by pumping the water around a loop of pe pipe under the beds. Personally I've found that even on 115F days venting the greenhouse with some 50% shade over the outside works well enough.

Best way to post a series of pics is to host in another account, like Flickr or Photobucket, then use the "share via HTML" code from that account and cut and paste into the body of your Garden Web post. You can preview your message to make sure all the pics look how you want and go in and edit and preview again if they look funky. The Image Upload in Garden Web is a relatively new feature and will only allow one pic at a time. It works but is slow going.