Sun/Lighting - Just can't seem to get it right! :(

[butterfly_muse]

Evening, all!

I am still trying to adjust my cattleyas to my window, and I am running into some conundrums. They are in a western facing window sill, which has an a/c vent underneath of it which provides cool, circulating air. I also got a big 3 ft by 3 ft piece of lace fabric, which I hung up against the window to cut/filter the light coming in near the end of the day when the sun hits that window directly. There are some trees outside, but for a period of an hour and a half or so the sun is above the trees. They are on top of a humidity tray, I mist them when it starts to get hot at that time of day, and they have their own little fan with them on the window sill to try to keep them cool and keep air circulating.

And yet their pbulbs and new growth shoots are getting purple, still. Do I need to get something not as hole-y as lace? Like a diffuser screen instead to go up against the window? Do I need to put another layer of lace over this layer? Or is it just because it's so damn hot, as most of you know, suddenly this week? We hit 97 today with a heat index of 103-110 in some places in the state and it's supposed to continue like this all week. They are as far back on that window sill as they can go and given that there's an air vent in the floor there I can't really put furniture over it to hold them. Also I think my fiance would have a big issue with me leaving the blinds up while we're gone during the day if I did shuffle them back another 6" or so onto a bookshelf that is next to the window.

What can I do??

Edit: I have moved them back further and to the back of their little plates since that photo was taken. It's just dark so I couldn't take a new photo of what the light looks like through the lace...^^;;

[butterfly_muse]

I was just wondering if the holes in my lace are too large and are letting through too much direct light? Do I need to get something that has much smaller holes in it to diffuse more?

[brn_thmbs]

I grow my Catts outside in the summer and they get direct sun in the morning until around noon and again evenings starting around 530. They typically need a fairly good amount of light.

[butterfly_muse]

Originally Posted by brn_thmbs

I grow my Catts outside in the summer and they get direct sun in the morning until around noon and again evenings starting around 530. They typically need a fairly good amount of light.

Then why are mine burning? If I'm not mistaken, the morning sunlight isn't quite as intense as the afternoon light? I could be wrong on that..but the sun swings around to that side of the building around 3:30 and is super intense until around 5:30-6 and then it gets low enough that it's behind the trees again. =\ I don't understand, I'm trying so hard to make them happy.

[WhiteRabbit]

It's normal for new growth to be purplish. And even if foliage turns somewhat purplish - it's fine if the plant isn't burning.

I don't think you need to stress so much - I don't use fans (tho lower daytime humidity here in summer, and windows usually cracked to let in the ever present breeze). Mine on windowsills ALL get sun hitting them for a while. The outside ones may be in the sun a couple to several hours.

If you are having extreme heat, just move them out of the windows til the weather is not so hot. We just went thru the same here at the beginning of the month (highs upper 90s to just over 100). All my orchids that normally get afternoon sun got moved. They're fine for a few days (or more!) without the light. (Mine were out of windows for a bit over a week - outside ones in a shady spot for the duration).

Take a deep breath! Relax!

---------- Post added at 07:29 PM ---------- Previous post was at 07:27 PM ----------

Originally Posted by butterfly_muse

Then why are mine burning? If I'm not mistaken, the morning sunlight isn't quite as intense as the afternoon light? I could be wrong on that..but the sun swings around to that side of the building around 3:30 and is super intense until around 5:30-6 and then it gets low enough that it's behind the trees again. =\ I don't understand, I'm trying so hard to make them happy.

Are yours burning, or just having purplish new growth and/or foliage?

If actually burning, it could be they need acclimating to the higher light, temp, combination of both - if it's extremely hot outside, move them from the window

[butterfly_muse]

They're just turning purple-ish. I'm less worried about my new growth than my pbulbs because I know that's the source of nutrients and water for the plant so I'm afraid of hurting it. I've never had cattleyas before and I lost a few phals due to actual sunburn so now I'm totally paranoid about damaging them..especially since I'm reading everywhere to not let them get direct light, lol!

[WhiteRabbit]

Originally Posted by butterfly_muse

They're just turning purple-ish. I'm less worried about my new growth than my pbulbs because I know that's the source of nutrients and water for the plant so I'm afraid of hurting it. I've never had cattleyas before and I lost a few phals due to actual sunburn so now I'm totally paranoid about damaging them..especially since I'm reading everywhere to not let them get direct light, lol!

Most Catts are not delicate at all. I grow some outdoors year-round - taking temps of over 100 for short periods and near freezing for short periods (I really push the cold temps on quite a few)

Yeah, I don't know what people mean by "no direct sun" - I figure they must mean something different by "direct sun" than I mean by it... I can't imagine getting many Catts to bloom with no direct sun - unless they get dappled light all day maybe ... or maybe they mean "over-head" sun when saying "direct sun" ...

Like I said, it's normal for many Catts to have purplish new growth, even in less than "strong" light.
During the heat spell, move orchids from the west facing window, to be safe. They definitely CAN burn in afternoon sun when temps get high.

[butterfly_muse]

I'll move them away from the window during that period, then. Lol, and I define direct sun as the sun shining right on them with nothing but a window pane between them and the sunshine...^^; except now there's lace!

Thanks, I feel better now at least lol.

[WhiteRabbit]

Originally Posted by butterfly_muse

I'll move them away from the window during that period, then. Lol, and I define direct sun as the sun shining right on them with nothing but a window pane between them and the sunshine...^^; except now there's lace!

Thanks, I feel better now at least lol.

that's how I define "direct sun" as well! I have no idea about other people ... Even my Masdevallias (quite low light plants) get a very little bit of direct sun early morning and/or evening ...

[trdyl]

Hi,

I have Cattleyas in a West window sill right up against the glass for several years and nothing filtering the sun except for the clear glass pane. They get direct sun between 2pm and 8 to 9pm. Also the highest temps I have measured there is 112 and the lowest being 40. Once they get use to that much light the do not burn. But if they are adjusted to be growing at lower levels they should be introduced to that much light gradually.