Consider the angle of the sun during the winter. The sun is lower in the southern sky and more light actually comes into the house than in summer.

I asked about this in a post about a week ago. Richard thanks for the explaination. Sun does come in farther but into the room but doesn't stick around for long.

WC- Thank You for addressing this! I posted recently about this. I think you have to be in z-5 to understand it.

I know what you mean about this time of year. Its a real pain to sort it out. Why can't we do this from year to year the same way? :-) I either have to build a "holding pit" in the shoppe and then move everything again, including lights ukkkgh! or just go for it. I thought my head was going to explode trying to sort it out some weeks ago.

I have new windows that are not frosted and much bigger. New variable for me. It put me in the same position as you. The ones I took inside that started to burn took me by surprise. This didn't hapen last year but I think we had more cloudy days and I have better windows and lights.

Not too sure of your current conditions that make you want to curtain or what you run for lights?

I wouldn't curtain unless you like to run around in your orchid room naked ;-). We are too far north and winter is coming. Let them have the light but watch them. I assume you are worried about burn? If so, curtain it for a week or 2. You have glass; acts as a filter. You can also adjust your window screens for a "shade cloth" effect. That's really all it takes. I can acclimate anything with some time/effort in about 2 weeks.

I curtained some new plants for 2 weeks South obstructed but it gets sun from 10:30 -2/3. Pleuros. The curtain is off and I am running 42w cfls. Now I don't think I have enough light ! :-) Just received an orphan oncid 10 days ago. I put it outside and I am letting it burn. Sounds cruel but ultimately it will be better. Did this with a private purchase plant this summer. Burned all the old crappy underlight growth off of it. The new growth is beautiful and has 3 new growths instead of 1. I know you can't do that with everything. I swear the orphans give me courage to experiment!

I have also noticed that the angle of the sun is giving some of my guys a little burn, even outside. (yes I have a few outside that need cooler conditions, sederea, oncids (ortho-novum), Twinkle, SB (I could care less about) paphs, neos, cloud forest, a special situ-collected very cool growing lycaste, other non-orchid tropicals) They are receiving less actual light but none the less, starting to burn or freckle. Twinkle is making tons of spikes suddenly. He broiled all summer in direct light without a burn. He is burning a little now and I had to shade him. But I see that the pre-mature spikes are now advancing and no longer "stalled". That goes to show you how pitiful our light is in z-5 in summer. Sederea is shooting up new new leaves and roots, in fairly direct sun. My hybrid neo same but burned on the old lower leaf growth (1 leaf each side of 1 fan) but has a new fan and roots are going nuts. My Ang Sus hybrid. is ripping giant new roots (indoors) in the W window with an 85 w cfl. Not a burn on him. I did not turn the light off on his side or use the screen. Phals are also getting purple edges (indoors) but I know they will green back up. Saw that during summer outside.

Obviously, Spring is so much worse than now with this issue. I remember that I was getting burn in spring rapidly. This Fall I am opting not to curtain in the big windows. I would need to have custom curtains made. Chose to solve the problem by simply turning off the lights in the afternoon for a few hours (W s.west window) and adjusting the window screens. I have the timers that I can turn off and on many times a day. The ones that had a little burn have stopped it . I am not really pushed about a little freckling on an asco or vanda though. The lights are back on all day. The all acclimated back up and are still sucking down water like bandits and pumping out new roots/growth. I want every last drop of light I can get while I can keep the day temps at 80 sans adjunct heaters and drop them at night !

Clara

Richard is right-- it's the change in the angle of the sun. Instead of going by overhead, it goes by lower and the sun slants into the room much further and stronger. For the same reason, the house shades more of the deck for longer now than in high summer.

I had this problem for a month or so last March or April-- leaves getting a little warm on some phals in my south window. Frost had killed the new leaves on a tree near the window, and in one night the light was considerably stronger instead of coming on gradually. Other years, the change has been gradual.

Sheers look pretty, but I prefer to have the sun and see the sky, so I don't do the sheers thing. I like unobstructed windows, even where there are no plants.

I just turned a fan directly on them for a couple of hours a day while the sun was shining in hot. Worked just fine, no burn. Same thing in a west window-- a fan blowing right across all of them kept them from burning.

I do have that film on the glass, put there by the previous owner. That may make a difference.

I personally would resist the sheers thing just because most advice does actually underrate the light that acclimated orchids can take. I try to maximize the light for more growth and blooms.

You can set a timer to turn the fan on during the critical hours.

When I first put the plants back in the window, because of the slanting fall sun, some of them get sunburn. One thing that works is slipping a piece of white tissue paper over them temporarily when the sun is strongest. It acts like a sheer curtain but can be plucked out of the way when the light starts fading. This is only necessary for a couple of weeks, until the plants get acclimated to be ing inside again.

Last year, an experienced grower said that for my E/SE exposure in the Minneapolis area, I needed sheers for 2 months in the fall and 2 in the spring. With my memory not cooperating sometimes, I don't remember which 4 months they were talking about, so I asked here.

It may be that a couple of weeks of sheers would do it, if the plants get used to the different angle of light.

All the orchids came inside on 9/11/07, so they should be used to light in the orchid room by now.

Any perspectives/experiences appreciated.

Whitecat8

Grow indoors in the same SW and W sun and the plants will burn without fans. I have small table fans, and stick them a few feet from the plants closest to the windows. I pull the Phals back about 8 ft and they will still get some sunburn.
The sun doesn't hang around long, but it is very hot.

It hit 90 in NY today. I moved most back outside 3 days ago. I think they will all get schleped back in Friday. I keep chasing the sun, wind and warmth. I keep telling myself 'its worth it because there's so much growth going on.'

Just get some small, cheap table fans. Target had a bunch on sale.

Jane

Your call, whitecat, and I don't even know for sure what plants you are worrying about. If they are the thin-leaved delicate type it may be another matter.

But the thing is, with the sheers on, they aren't acclimating, so you'll probably have the same problem of tender plants when you try to take the sheers off in a couple of weeks.

Is it possible that just moving them a foot or two away from the window for a week or so, and then gradually moving them closer would do it? Don't forget, light intensity is cut *in half* for every foot away from the source. So what's too strong near the window might be okay a foot or so away.

I guess Howard has made us all into light freaks here. Your grower friend doesn't sound like one-- 4 months of cutting the light with sheers sounds pretty drastic to me given how little light there is November to March. (We have 3-4 sunny days out of 7 during that whole period).

That tots up to 8 months of weak light. I couldn't stand it meselfn. I'd get that Light Deficiency Affect Disorder, for sure. I need that ole sun coming in. My kitties do, too. They love to fry their little bottoms in it, and move around the house to bask in it all day.

But I don't want you to burn up your plants. So take what I say as well meant mumblings.

Don't forget, the fans (recommended by Jane and a few others here) worked! Maybe fans and two feet away?

I also agree with Clara-- the new leaves come in tough and already adapted to the higher light-- beautiful. I've been noticing that with some violacea type phals I bought this summer. The old leaves are thin, flappy, light green and tender, but the new leaves are coming in tougher and harder (and brighter green).

Mehitabel, do you grow any Equestris? I know you are growing under lights, but would like any hints on these plants.

I have one which has been outdoors all summer and is still out with the cool nights. It doesn't seem to be following 'the book' in the way it grows. Thought they stayed small!

Just wondering how you treat them.

Jane

Fellow light freak here. From mid-Oct to mid-April, the orchids get unfiltered SE and SW sun. The sun lovers get supplemental lighting in the form of fluorescents. No burning and makes for better adjustment in the spring for the outdoors.

But I'm in the Northeast. Sun intensity may be different in the Mid-West. Ultimately, no one knows your orchids and growing conditions better than you so trust your experience.

Jane, I don't have any equestris species-- have a few equestris hybrids, some 50%, but that's all. Just growing those with the rest of them.

I checked orchiwiz for CCM awards: one was for a 12" wide plant in a 6" pot; a second one was in a 6" pot, too. Twelve inches isn't the biggest, but not exactly what I would call mini, either.

Sounds like you are getting great growth on yours. When they say "compact" is it possible they mean the spikes instead of the plant?

I bet if you emailed Peter Lin at Big Leaf, he could tell you. He's very nice and helpful with species questions.

Thanks, everyone. DH is always saying these orchids need to toughen up - they live in Minnesota now. LOL This year, I'll watch them carefully in the unfiltered light. The sheers are ready to pull across at any minute. Whitecat8

DH is right! Only the bold survive z-5.

Be Bold or be Burned!

Clara

PS WC now that the equinox has passed it is easing up. Use the curtains in spring while the "babies" are acclimating. (for 2 weeks not a 1/4 of the year!!) That is almost a must.

Clara - DH will love your slogan/threat! He'll probably chant it every time he walks past the orchid room.

Not using the sheers might help the Potinara rebloom. It's making a slow recovery from the extreme heat summer before this last - spikes got fried when we had to be out of town, and the leaves split and got leathery. It's got a few sheaths going now. Holding my breath. Whitecat8