Are There ANY Orchids That Can Take Full Sun?

[mauraec]

I realize that orchids are sensitive to getting overheated, as well as sunburned, but, as I watch and move around the high-light orchids on my deck, it's obvious that some of the catt leaves have been sunburned at some point, so I have moved them to shadier places. On the other hand, few of my Encyclia hybrids seem affected by either sun or heat - although all are positioned where they reeive no direct sun from 11:00 - 4:00. But my Cyms. are another story altogether - I've always had them in full sun, as much as possible, into November and sometimes even September here in Atlanta, with little protest from them - this year, however, which happens to be an historically cool, cloudy, and wet summer (for ATL, that is), my Cyms are showing signs of sunburn and general unhappiness. Obviously, there are myriad explanations for all these things, but I have done my homework on footcandles and temperature tolerances, and try to position them accordingly. But has anyone ever seen the various orchid magazines showing, for instance, Catts. in situ, in South America, in full sun? I assure you, there are many examples.

Just wondering whether it might be possible to move some of my more crowded outdoor orchids into a sunnier area. Any ideas, all you orchid growers with decades of experience????

[coeruleo]

good question. i wonder about seeing orchids in the sun in photos, as here in california they roast quickly. i just had to hang shadecloth already, as some were beginning to get sun, and loosing leaves, like encyclia alata. i have been trying to find more sun tolerant plants, and got a small shomb tibicinis, which had some trouble shipping and acclimating, but is sending up a new growth now. it does not get full sun, but dappled sun in winter. last winter i burned a ren tom thumb, so it got moved into the oncidium area. it likes it there. i replaced it with an oncidium cebolleta, and am seeking an ansellia. i did buy an eulophia petersii, which says to 'grow like an aloe' which for me means not much direct sun... i think these photos from the tropics must be from places with lots of cloud cover? it just doesn't work here. you can supposedly get away with some like the tibicinis, but i hear they tend to loose all their old leaves, like mine did, and only new growth has leaves.

[pavel]

There are a lot of factors, I believe, which come into play.

Full sun = what? Full sun all day long from morning until sunset? Morning only? Afternoon only? Full sun in the tropics? Full sun at one of the poles? Full sun on a mountain top or at sea level?

What kind of humidity and air movement is usually present? Under cool and/or breezy conditions plants can handle a lot more sun.

What is the genetically determined tolerance of a species? If a hybrid, what was the tolerance levels for its parents and which parent did it take after?

Was the plant properly hardened off? (Important point for any of us who grow our plants indoors at least part of the year.)

I have some catts that can handle full unobstructed sun on my balcony from 8am-2pm. (My balcony literally gets hot enough on a typical summer's day to burn one's feet ... to the point of blistering if one isn't careful and stands out there barefoot for too long.) I have others that are at the limits of their tolerant sitting by the glass doors exiting onto the balcony. (The glass itself does reflect/filter some of the intense sun out and because of the roof, the sun is finished shining on those plants by noon.) I have other catts for which even that would be too intense. They sit behind the "frontline" window dwellers, getting a bit of shade from them.

For cyms, baking the daylights out of them is typically the way to go. Now in Texas or other very hot often arid areas that could be too much.

As always, let the leaves be your guide. They will usually tell you what the plant wants (some special cases) -- though you still should know just what is "normal" for that plant.
Especially with catts:If the leaves are dark green, much more light is called for. Medium green = could probably handle/use a bit more. Light green or purple speckling/purple blush to the leaves = plant is at the upper limit of its light tolerance.
Cyms: Chartreuse (yellow green) is often the target color during the summer months (growing season), green during the winter.
Pleurothallids & phals: Aim for medium to light medium green.
Jewel orchids: dark leaf color is the norm.

[Tednz]

These will tolerate full sun as long as they are put out early.The best flowering is when they get even a bit sunburnt.
It is Dendrobium speciosum and a lot of the Aussie Dendrobium's will take quite a bit of full light.

[coeruleo]

i have a dendrobium kingianum, it seems to be able to handle the most sun so far. it gets full sun until noon or so. then bright light through 2 layers of shadecloth. bloomed it's brains out this spring.

[stateless]

Pavel hit the nail on the head, it all depends, with cloud cover where I live and you can still get sunburnt, I think the key is slow steady introduction. The only thing I grow in full sun are my terete vandas , there are a few dens that are on the edge of my higher light vanda area.

[mauraec]

Thanks for all the input! OF COURSE the answer is always "It depends"'! I AM trained as a lawyer, you know, and that's the standard answer to every client's question.
I watch my orchids, both inside and out, pretty closely. What I haven't yet done is to sit in front of my sliding glass doors all day and watch the changing sun exposure. Every once in awhile, I notice that full unfiltered sun is shining @ say, 3:00, on several catts or encycs and I frantically search for a spot in the shade for them - no small feat on a deck that is 8x10 at the most, with an overhang about halfway over it. This weird rainy, cloudy summer I can even put my Paphs and phals outside for a bit more light and humidity on occasion.
But, I am really perplexed by the in situ photos I see of native species in tropical climates, seemingly without a filtering leaf in sight. There may be many reasons for this - complete acclimatization being the most obvious. I have several catt and encyclia species that I've seen growing in full sun all day in their native regions, whereas mine really do seem to need bright but filtered light. So I'm wondering if I can toughen them up a bit, accepting some to be sunburned initially, but maybe they can take that and thrive after a time. I was looking for good starter candidates - my E. radiata or pentotis? The C. maxima, skinnerii, labiata, or a Laelia anceps? I'm specifically interested in growers' experiences with allowing a particular orchid to absorb all the sun all day long, in a very warm climate (the usual summer here in Atlanta ). The humidity stays at a minimum of (50% during the day and can reach 70 or 80% on a regular basis at night or on a misty, rainy day - which is why I leave my windows open and run fans everywhere instead of the AC. People from places with long hard winters know that the minute the outside temps hit the 60s and up, you open every window and door that you can and leave them open until its necessary to turn on the heat again. Here in the Deep South, the natives close everything and turn on the AC from April through October. I wonder if certain orchids are like one or the other... Just pondering while I can't settle down to sleep yet and am putting off the nightly pain and sobbing episode.
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[catttan]

I concur with Pavel. Generally speaking in our country the terete, semi-terete vandas, aranda, mokara are grown in full sun in our cut flower nurseries, but the same plants begin their early life as seedlings growing under shade. They are then hardened by slowly reducing shade ('acclimatisation') before planting out in their permanent beds.Strap leaved vandas are never grown in full sun. Some hardy hard-cane dendrobiums do very well in full sun.

In our tropical jungles, species are seldom exposed to full sun for any length of time - the exceptions being the deciduous dendrobiums of the tropical monsoon farther north from the Equator (north of the Tropic of Cancer) that experience a cool dry winter, typically from Dec-Feb. During this period the trees lose their leaves, including most of the dendrobiums, and are exposed to almost full sunlight. This period also stimulates the deciduous dendobiums to spike and bloom from Mar - April. This time too is when photographers take pictures of those fabulous of blooming dendrobiums in situ. In Malaysia Arundina and Spathoglottis grow in full sunlight in grassland areas. Another species that thrive in open sunny situations is Pectelis (Habenaria) susannae and, of course, the Kinta Weed, Papilionanthe hookeriana.

[siaogu]

My Arundina and Spathoglottis grows in full sun, 365/24/7.

[zainal abidin]

My Rhyncholaelia digbyana and antelopes dendrobium they really love full sun light some of the Dendrochilum especially in highlands they thrives very well on open area without any sun burn at all really very weird.