Wow, that is a vast and varied collection, kudos. 50% shade is not a bad place to start but you have said nothing of the temperature management devices in the GH. The more light tolerant plants can themselves be used to shade those that are more tender so don't stress about finding extra shading. Too much is made of phals and paphs and bulbo's needing lower light. They don't. In the dry season when cloud cover is minimal there are plenty phals that receive the equivalent of Oncidium, maybe Catt level light!Some of the difficulty in re-blooming phals and paphs IMO might be due to the common wisdom of giving these orchids minimal light year round in the mistaken belief that they need it.
H

I bet there is more light variation than you think. Walk around with your light meter, measuring at different heights in addition to different locations. The same goes for temperature and humidity.

You have to use the various height levels in your glasshouse and site various orchids in the best possible spot.
As for growing all those orchids to optimum levels in the one enclosure. Good Luck. It will be the usual story, some will grow well and flower, others will limp along.
Time to think.hmmmmmmmmm, what Genera do i really like and start to concentrate on those.
As Richard says you have to take into account Temperature and Humidity as well.
In all the years i have posted here no one has ever come up with settings of temperature, light and humidity to grow everything well in the one enclosure.

I consider myself lucky to get responses from you three in such a brief time! I did think of posting other info, Howard, but things are in a state of flux. I haven't brought electricity in yet, so I have been manually opening the shutter (which will work in conjunction with my exhaust fan, using a 2-stage timer). I am using 3 roof vents, 2 Bayliss which open gradually around 70 deg.F., and one manual one. They are all on the same (leeward) side. If things get too hot, I open the doors. I have one large circulating box fan which uses an extension cord for the time being; it is on 7/24. We have had a long grey spell, so there has been time for "my" electrician to go on vacation. I hope he will be here this week.
So far, the Day High has been 88.5 deg.F. and night Low 56.3 deg.F. over the past few weeks. Humidity has been a high of 86%, low of 36%. Regarding your comments on light level requirements being flexible for the phals, phrags and bulbos, since being in the gh, two bulbos getting considerable morning light have got yellow tips on a few leaves, and one of those has the yellow portion turning to brown. Maybe I didn't introduce them slowly enough. The Paphs have taken on a lighter leaf color, but seem ok. A few of the Phalaenopsis (still in the house) have leaves with that reddish tinge which signals too much light (imho), so that is why I am concerned about putting them in a situation with considerably more light. I will try to introduce them very gradually.

The reason I don't tend to think in terms of putting the phals and paphs under other plants is that they are both prone to crown rot, and I worry that water may drip on them from above and subject them to that. A slanting shelf might be an idea.

Richard, I will try to establish some meaningful data once I have the electrical components working, and perhaps have a few more plants in there (thinking maybe I can increase the humidity by putting in some of my Bromiliads). Hopefully you are right, and I can identify some zones within the gh which vary in these respects.

Arthur, your words are discouraging, but the orchids are sure to benefit from the new environment over the old (which was lower temp, light and humidity in my house). Most of them should be comfortable--or able to adjust--to an Intermediate gh. There are only a few real oddballs. I *am* having a bit of a time trying to identify appropriate placement for those plants with similar requirements in one respect (i.e.,light), but different preferences in another (i.e., humidity/water). Not ready to give up yet.
Thanks for your input,
Ann

My high-light orchids, like Vandas and Catts, get hung up close to the roof. My low-light plants, Phals & Paphs, etc., are on the benches underneath. The half-light bunch, like Corys and Trichoglottis, are on the brighter wall, and the lower light mounted plants, like Aerangis and Angraecums, are on the lower light wall. I have fans at three levels which dry them all out quickly -- sometimes too quickly during scaldingly hot days in summer.

I also have an 8' long wire closet shelf on the dimmest wall above my potting bench where I grow seedlings and dormant Catasetums under shop lights.

I have never had a crown rot problem. However, before you hang plants above other plants, be sure they are healthy and/or not bug infested. Those I have any health doubts at all about hang from the roof above the center aisle where they can't drip on other plants.

CJ, That's an enviable collection you list on your Page! Although my gh is not super strong, it should be able to support the catts from the rafters. Do you take yours down for watering?
I am finding that the one large box fan I have is drying out the mounts; I'm dousing them daily, and this is likely to increase in the summer. Do you use a mister/fogger?
I appreciate your input; it sounds very logical.
Ann

I'm with cj on this, so long as you have the orchids which can take more shading the rest i'm sure the majority will do nicely.

I however have crown rotted a phal and not had much luck with them in general in the greenhouse.

RP1

I have the 50% aluminet cloth over the greenhouse but for the paphs and phals I hung another 50% cloth on the west side of the gh. This area gets morning light in the 1500-1800 range until noon but drops to 800-1000 in the afternoon.

Brooke

Ann, I don't use misters although I have a a couple sets in the factory boxes which I never got around to installing. My GH stays fairly humid even on the hot low-humidity (20% outside) days of summer.

I water with a hose with one of those cheap wands from Walmart. They usually last about 18 months.
I use a box fan (only in the summer) at ground level under my potting bench where I mostly grow big pots of large bromeliads; the water in their reservoirs aids in humidifying the GH and catch any debris from the plants just like they do in the wild. Less for me to sweep.

I have an oscillating table fan, about 16" diameter, at the end of my workbench which ventilates the mid-level of the GH, and I have a small 10" fan on a high shelf which keeps the upper levels of air moving.

I do have a big exhaust fan and vent in the GH, but it is programmed to only come on at about 95F, which almost never happens. I do not have roof vents, but I have 5' tall casement windows which reach to the roof and vent the hotter air. They stay open all summer. And then there is the storm door entrance, which right now is changed to screen from glass. Add a bottom vent which adjoins a cool under-deck area for passive ventilation.

Part of my lack of severe heat problems comes from the house blocking much of the direct mid- to late-afternoon sun, leaving it bright but not sunny during the hottest time of the day.

If my GH roof is covered with mold and algae, I don't need to use shade cloth. When it is clean, I use shadecloth only on part of it since the fiberglass is opaque anyhow and dims it down about 30% by itself.

Be creative. Cheap electric conduit pipe (10' lengths)works wonderful for hanging plants from. Tack wire mesh up on the walls for instant mount space -- 1" or 2" square mesh works well.

If you have a local society, join and politely invite yourself to other members' GHs to see how they deal with theirs under your climate conditions. This is probabaly the very best of the best advice.

Good luck.

I am in So. California as well. I grow my phals on the bottom shelf of my benches. Haven't had any problem with rot or sun burn and they have bloomed just fine. I have one layer of 75% shade cloth on my greenhouse.

I only water in the morning and my misters only turn on when it's hot, so the water dries before night fall. I run my misters above my benches and they are activated by a thermostat and run on a repeat cycle timer using an interval of 1 minute per every 5 minutes.

I also have 50% cloth on the roof, with high light plants on upper shelves. I nestle my few phals and paphs under that shelf (with no plants in a direct drip line from above) and use a small piece of shade cloth on the shelf to make a shadier space below.

This is a great question and one I've been searching for a simple answer too. Arthur is probably right!!!!!

It's very difficult to grow such varied genera in the one enclosure........the only solutions I've found end up being very unsatisfactory to say the least.

One option is that I grow my Pleuro's and Paphs on the bottom shelf under my higher light plants. The other options I've used is the put an extra layer of cloth over one side of the house so I can grow low light on that side and the higher light on the other side.

One day I will have two houses!!!!!!!

My problem is space. Like any devoted orchid addict, I will always have more plants then I can comfortably stuff into the GH come winter. But I can grow any species or hybrid in it which likes my temperature range (warm-growing): From Corys to Pleuros to Aerangis to Vandas, Cattleyas, Paphs, Phrags, Phals, Catasetums, Cyrtopodiums, Trichoglottis, Stelis, Neos, Stanhopeas, Rhynchos, etc, etc. There is a place somewhere in my small greenhouse that each plant will like. The trick is to figure out where, and that comes from research about the natural habitat of the particular plant and a close study of my greenhouse conditions -- this area is warmer/cooler, gets more/less air circulation, brighter/shadier, more/less humid, wetter/drier. Even small greenhouses have surprising diverse microclimates once they have lots of plants growing in them. The plants themselves, orchids or otherwise, help create many of these climate niches.

Thanks for your comments, everyone. Audmer, I was thinking of dedicating a drip irregation line to some misters which would help with low humidity problems I am having. I have a timer already installed. But I was thinking of only misting the high moisture loving plants (the ones I normally water more than once a week). It seems from your post that you mist everything. How high is your line above the plants?

My misters are about 4 feet above the highest shelf on my benches. Most of my orchids are either mounted or grown in straight LECA or s/h. I'm a chronic over waterer so I like to use media and pots that dry quickly. My misting system runs primarily as a heat reduction system and not as much as an irrigation system. I live about 20 miles inland in San Diego county so it gets pretty hot and cold.

For humidity I would run the misters on a repeat cycle timer. It'll allow your misters to run for a brief amount of time but multiple times per day which is most optimal for humidity and saves more water. I used to run a schedule based timer with 7 settings available. I would have the misters run for 10-20 minutes every hour. It didn't work very well. I experimented with longer durations but it didn't help with the heat or humidity and sometimes made things sopping wet. The repeat cycle timer has worked like a charm in keeping a more stable humidity and it has also saved water so I have to fill my 50 gallon tank less frequently. I also assume it's better for the plants since the media doesn't get as saturated with water.