Light adaptation

[rtsingleton]

In everyone's experience, how much have you been able to adapt orchids to more light than 'should be' allowed on them? I'm sure it varies by species but I was just curious as to overall how much you could slowly acclimate orchids to more and more light, if possible at all.

[Ross]

Sure it's possible. I grow my Phals right now (I only have three at the moment) in a south window where they get full sun when it shines. The leaves are pretty light and reaching for the window. The temps drop to approx 60 degrees at night. The plants are in spike right now.

[Aceetobe]

There is a component of heat involved.

I have several zygos, and I've had them out in full full sun all day for a couple years. They are fine, grow well, bloom a lot. Once the temperature jumps they get burned though.

As long as the leaf temp doesn't get too hot, most plants can take a lot of light - as long as you slowly adapt them. You really have to watch the watering and humidity in the high light situation because they dry out super quick. Another thing to pay attention to is the root temperature. Clear pots plus direct sun is lethal.

[Becky15349]

Originally Posted by Aceetobe

There is a component of heat involved.

I have several zygos, and I've had them out in full full sun all day for a couple years. They are fine, grow well, bloom a lot. Once the temperature jumps they get burned though.

As long as the leaf temp doesn't get too hot, most plants can take a lot of light - as long as you slowly adapt them. You really have to watch the watering and humidity in the high light situation because they dry out super quick. Another thing to pay attention to is the root temperature. Clear pots plus direct sun is lethal.

I completely agree with this - and I learned all these lethal things the hard way This summer I moved to an apartment with south-facing windows, and they are all doing ok...I haven't lost any, but some are having a hard time. They do better when the humidity is higher, they can dry out quickly, and when they have a fan on them to keep the leaves from burning.

[Tsuchibuta]

I put all my Phals outside with the rest of my plants and some of them got nearly 5 hours of full sun with no damage and actually are spiking now. I agree if you slowly acclimate them most can take alot of light. I think it's like us we will "burn" less if we slowly acclimate to the sun, but I think in both cases that the intense light will speed up the "ageing" process. As I have noticed that in my plants that usually grow in less light seem to grow faster and loose leaves faster than those in lower light. That being said, I would assume that more fertilizer would be needed as well as the plant would be using more energy in full sun. Though I am no botanist, I just grow based on my own observations.

[Ross]

Something I forgot to mention, I am at 45 degrees Latitude in Michigan. The original poster is in Texas. One is from Ohio. Those are at differing latitudes. When I say "full sun" that light is probably half strength of Texas light. Once again I must state, a light meter (a good light meter) is the only definitive answer. I measure 3500-4000 foot candles in full sun. If others posting an answer would do the same then the original poster could get a better picture. Just my 2 cents.

[Aceetobe]

I'm in San Diego. I'm guessing my Zygos get > 6000 fc for about 6 hours a day. Once again though, I run around like a madmen to take them into shadier environment when the temperature is over 85 or so.

[Ross]

Originally Posted by Aceetobe

I'm in San Diego. I'm guessing my Zygos get > 6000 fc for about 6 hours a day. Once again though, I run around like a madmen to take them into shadier environment when the temperature is over 85 or so.

See, that's my point! 6000 FCs is really high. I couldn't generate that even with high output t5 lamps. Most I can get is 4000+ FCs. So if I say "high light" or "full sun" that is way different from your situation.

[rtsingleton]

If they were in full sun where I am during the hot days of summer the leaf temperature would probably reach 110-120... Cooling a portable greenhouse is a complicated situation...

[Ray]

Some plants don't bloom as well in excessively-bright sun - just too much stress, I suppose.