Can a mini phal tolerate weak afternoon sun?

[Fran20]

I have a mini no-id phal sitting on a coffee table in the center of my living room. I have SW exposure. At this time of the year weak direct sunlight has started hitting it for about 1/2 hour around 5PM. This has been happening for about 1 week. Leaves don't appear to be getting lighter and aren't heating up either. It finished blooming and is sending up the beginnings of a new leaf. I don't like moving the plant back and forth too much. My question- would any type of direct sunlight, even weak sun, be damaging to my phal?

[rbarata]

I think any damage may not show up in a short term but maybe with time it will may have some kind of consequence because it's not the ideal light condition.
Phals are low light plants.
This is only my oppinion as I don't have enough info to give you a trustable advise.
If you don't have any other option, let it stay where it is and see how it goes. But remember, in winter the sun is "lower" so this condition will remain until spring and as winter progresses the direct sun hours will be higher.

[SouthPark]

Originally Posted by Fran20

My question- would any type of direct sunlight, even weak sun, be damaging to my phal?

A nice test is - take 1 phal ... maybe this particular one is as good as any, and watch it like a hawk. If this phal can keep handling the sunlight with no signs of damage, week after week after week, building up to months, then chances are that it can handle that amount of sun light level, which may even be good for it.

[Roberta]

If the light is weak (and it falls off as the square of the distance from the window so if back, it's weaker than it looks) you're probably OK. When the sun is at its peak for that spot, feel the leaves. If they're not overly warm to the touch, I don't think you'll have a problem. (It's the heat of too much sun more than the lumens that scorches leaves) I have Phals in the greenhouse, they get a lot more light than theory says they should, and they not only grow well they bloom. But they're acclimated to the spot.

[Mountaineer370]

FWIW, 12 of my 18 Phals sit in an unobstructed south-facing window. You'd think that would be a big no-no, right? I live in Michigan, so we're probably at similar latitudes. All of these plants get direct sun for several hours a day -- that is, on the days that the sun shines. In addition, because for the first couple of years, I had such trouble getting anything to bloom, and some folks here told me I probably didn't have enough light, I am now using a couple of full-spectrum fluorescent floor lamps over the table. The plants are all happy, blooming like crazy, and I have never burned any of them. I don't know if it's my fairly new high-efficiency windows or what, but they just don't get hot.

The other 6 Phals are in a north-facing window that never gets any direct sun. Those plants have the same type of floor lamp over them. They are all doing well, too. Go figure.

Just goes to show you, I guess, that there can be exceptions to any of the "rules" we are told apply to growing orchids. Growing conditions inside each of our homes or greenhouses can vary considerably, so we need to pay attention. But I think, if your Phal has had a chance to get gradually acclimated to its current location, you're sure it's not getting hot, and you're keeping a close eye out for any problems, it will be fine. A half an hour of very late afternoon sun is not very much.

[Ray]

Cheri's post is loaded with different subjects, that it brought out my inner Bill Nye.

1) Plants can adjust to different light levels. They may skip a year of blooming if moved to lower light, but will compensate and do fine as long as the reduction is not too drastic.

2) In nature, most phals are understory plants that get no direct light whatsoever. Tropical forests can be dense! The best-grown phals I've ever seen were in a greenhouse so algae-covered that it was just plain dark.

3) Low-E windows reduce the light transmission to about 75-80% - but that's light that is perpendicular to the glass. All windows reflect a good bit of the incident light that comes in at an angle, which is precisely what sunshine does.

4) Roberta hit on a good point about the glazing being the "light source" to indoor plants. Sunlight does not really go through glass (or other glazing materials), it is absorbed on one side, travels through it and is reradiated with reduced energy on the inside. The intensity really does drop off at an inverse square of the distance, but because the area of radiation is so large, the level doesn't actually drop off that rapidly.