To Burn, Or Not To Burn...

[hosshead]

....that is the question!

So many orchids require HIGH light to bloom*, I've read remarks that, if you want your Ansellia to bloom, you must resign yourself to leaf burn, it requires so much direct light.

So, how much burn do we generally accept, what do we think about Ansellia and how to give enough light without severe burn?
What about catts and direct sun?
Especially at high latitudes?

Some of the finest flowering orchids I've seen had some moderate leaf burn.
Then again, many don't.
Lower latitude orchids seem to get enough light year-round that they don't need direct sun....

I'm interested in the highly respected opinions of this forum, now it's summer and my mind turns to this question every year.

*Of course, we are not talking about the shade-lovers....

[Magnus A]

The statement of the Ansellia is wrong as I have seen that specie in flower without any sign of leaf burn!

And it is not the light in itself that "burn" the leaf, it is the heat that damage. Though high amount of UV light can bleach a leaf, but then they turn white and not black.

So, can you keep the leaf temperature down you can hit them with almost as much light you want!

[Gage]

Hi, Sammy! Regardless of the genera, I have a hard time believing that any orchid should require actual leaf burn in order to bloom. But in higher latitudes with short day lengths maybe that is the case. I always try to put each of my orchids in the highest light I am able to provide without burning them. However I think I remember reading on one of these threads somewhere that some orchids will refuse to bloom in higher light. I can't remember which species they were referring to, but I do believe this is the exception and not the rule.

Maybe some Canadians can chime in on this great question!

[Leafmite]

Introduce them to the required light slowly and they aren't as likely to burn. Also, sometimes 'high light' for orchids is not 'high light' for other plants...usually, it isn't. Temps and whether you have a constant breeze or not can also have an impact. And, yes, the degree of protection the atmosphere gives your plants is also a consideration, as well as the angle at which the sun hits. It is fine if you get plants with red/purple coloring that need high light to bloom as that won't kill the plant and means that the orchid is getting the maximum light.
PS
light green/yellow leaves can mean too much sun for orchids, too.

[Magnus A]

Originally Posted by Gage

... However I think I remember reading on one of these threads somewhere that some orchids will refuse to bloom in higher light. I can't remember which species they were referring to, but I do believe this is the exception and not the rule.

For at least some species, there is a need for a solid dark period every night and it is easy to compensate lower artificial light levels with longer time of illumination. The plants get to short nights and have no time to recover.
You can compare it with athletes that need to rest and can not train hard for 365 days a year.

[Bud]

I have my Mokaras in direct sun .... I had to gradually wean them from indoors to outdoors last spring.
The direct sunlight only happen from dawn to 11am for the taller buildings shade it and brings back the sun by 5pm.
This is in the southfacing fire escape area of my apartment which is lucky for me because the sun will burn leaves from 11am to 3pm....
it is very humid and hot this time of year in Manhattan so I am scared that my buds will blast.... I would rather have my Vandacious plants get the light they need and humidity fordeveloping the leaves and roots with such great hope that the heat wont damage my flowers

[hosshead]

And see, here is why we have OrchidBoard!

I've been a "Stan Man" for much of my orchiding life. Also very much into the Catasetinae group.

I have the typical mixed bunch of catts and dens and intergenerics....

I love the species orchids, do pretty well with things like comparettias and Osmo/Rossioglossums, coryanthes, coelogynes, phaius..... lots of shade lovers, as you can see.
This year I have gotten more interested than ever in trying some very high light plants, have acquired a large Ansellia, and a few Schomburgkias.
So, this year, I have gotten around to asking this one big question regarding high-light requirements and all about leaf burn....I'm quite motivated now!

So, thank you very much for your participation!

I just wonder what wild orchids do if they find themselves growing where there's a splash of direct light?
My dappled sun orchids,(those under trees for the summer), will get a burnt leaf-tip here or there, but they grow sturdily onward. The high light seems to really help them bloom happily. My stans are especially happy to spend the summer outside, hung high up under the orchid-porch roof,(never direct sun, unless it's by accident!), I also take the cycs and morms and catisets all out onto shaded shelves.
They get lots of the warm and humid and bright shade, no direct sun.

My Big Question is about the Catts and the Schombs and the Ansellia, then.

I think the acclimation idea sound very good, but shorter summers make it harder to accomplish.
Do we think a lattice can be advantageous with this?

[hosshead]

p.s.
Yes, I know that the Schombs are now called Myrmecophila, it's just hard to remember to say that after years of calling them Schomburgkias.

All these naming wars!

[dounoharm]

all my big catts have yellowish leaves, they need that sun to form big strong stems of flowers! the smaller the catt tho, the easier i go wiht light..,the little bitty mini catts keep greener leaves....at least that is the deal in mhy greenhouse.....

[isurus79]

You would be surprised at how much sun orchids can and prefer to take. Growing in Hawaii let me buy tons of orchids for fairly inexpensive prices and experiment. I actually found that my narrow leaved Stans did very well in Cattleya light and that my Cattleyas could take full Hawaiian sun for long periods of the day and they loved it. Catasetums are similar to Catts in that they love love love bright light, so long as there is adequate moisture during active growth. I think that low levels of sunlight is the most common mistake made by orchid growers. They love bright sun!! As a Canadian ex-pat, I doubt very much that the sun up there would burn well acclimated orchids of just about any variety. I'm here in Central Texas and my Clow. Rebecca Tyson Northen, Catt. walkeriana and Catt. nobiliors are outside getting full late day sun (130-6PM) in 95-100+ degree weather and growing like mad!! Just introduce them slowly to natural sun light and you will notice great growth and even better blooms!!