Direct Morning Sunlight...Does it need to be dappled?

[Plantcrazed101]

I'm looking at my Psychopsis and Oncidium right now, and they are in direct sunlight that is not shaded at all...they are sitting on an east facing window and the sun will definitely be gone by noon, but I was wondering if they can take that or if the sun still needs to be shaded in some way?

[Paul]

You likely will get a number of different answers as all orchids are not created equal and conditions can vary greatly not only by latitude but also by season. (What works fine and dandy during the winter may be too intense come spring.) Proximity to the window will also make a difference.

Typically, Psychopsis wants Phal light levels while Oncs want more.

Generally, the leaves will tell you what they think of the lighting you are providing.
Deep green: Could use more.
Medium green: Probably good enough but more wouldn't hurt.
Light green: Usually the color to aim for.
Yellow green: Too much, back it down. (Unless you are a Cymbidium -- in which case yellow green over the summer is a good thing.)

Also if the leaves get hot to the touch, back it down.

[camille1585]

Where are you located? That's going to make a big difference, along with season. I'm in the Netherlands, and my Psychopsis sits in a south facing window all year round with no ill effects. But if I were in southern Europe for instance, it would probably fry...

Paul gives a pretty good guideline for 'listening' to your plants. Also, plants which have been gradually adjusted to high light levels will do better than a plant quite suddenly placed there.

[Paphluvr]

Excellent answer from Paul.

[Plantcrazed101]

Thanks for the suggestions!

I'm in Austin, Tx. I have had to move a phal away from one of my east facing windows because it was turning bronze, and I have another that is about 4 ft from the window and looks medium green and is in spike.

[Raqsharqi]

That's interesting, Plantcrazed101! I live in Tucson and I've got my orchids about a foot away from our south, east, and west windows and they aren't showing any signs of stress. The sun just doesn't have the oomph now that it does in the summer...or even in February, when our position relative to the sun starts to shift.
It may not be at all accurate or scientific, but I have always timed my planting to tanning season! No matter how long I'm outdoors, I don't tan after August 15=/- or before February 15 =/-. I'm guessing that says something about our position relative to the sun, and so I begin planting outdoors in February and remove the shade cloth outside about mid August. I don't know if that works the same way in Austin.

[bil]

I wouldn't worry about dappling. It's VERY hot where I am, and I found to my cost, bu crisping a couple of phal leaves, that dappled light can have hot spots, and hotspots can burn a leaf quite badly as they cross it.

[camille1585]

Originally Posted by Plantcrazed101

Thanks for the suggestions!

I'm in Austin, Tx. I have had to move a phal away from one of my east facing windows because it was turning bronze, and I have another that is about 4 ft from the window and looks medium green and is in spike.

It also depends on the Phal's genetic background. Some of mine tolerate higher light very well (or even need it, like my phal gigantea), while some other ones seem to turn yellow or get sunburn if I keep them in the same spot.

[Subrosa]

Intensity isn't the only seasonal consideration. The changing angle if the sun needs consideration as well. A window under an overhang can easily get direct sun in the winter and not get any in the summer due to the higher angle of the sun.