Vanda alliance - how much light can they really take?

[dlbush]

I have five Vanda alliance plants growing outdoors. Four of them are seedling size bag babies (although one of them is quite large and has about 10 - 12 leaves already) and the fifth is a near-blooming size clearance shelf rescue with very few short viable roots. Four of the five are Ascocendas, but the fifth is a Vanda Rothschildiana (a seedling).

It's summer in Central Alabama right now and temperatures have been climbing up into the 90s (that's 32 - 35C) in the afternoons. Humidity is fairly consistently >50%, sometimes reaching 70 - 80%. I'm experimenting with growth media, so three of the plants are in baskets, one is potted in bark, and the other is sitting bare-root in a glass jar (the two that aren't hanging get about the same amount of sun as the hanging plants). I initially had the hanging plants on the same cast iron stand that I hang my bird feeder from, which gets direct sun from 6:30 AM - 12:30 PM and dappled shade in the afternoon. The plants I've had the longest seem happy - they are putting out new roots like crazy (half a dozen to a dozen new tips per plant). However, I did notice that the leaves were looking a little washed out and would get warm to the touch toward to middle of the day.

I have an app on my phone that measures light intensity. It's probably not very accurate, but under direct sun, the light intensity around my plants is WAY higher than the recommended 3 to 5 thousand foot candles for vandaceous orchids. My main interest right now is the get the plants to establish themselves - grow lots of roots and leaves. I haven't seen any new sunburn (some of the leaves had a bit of sunburn when I got them), but a few of the leaves do appear to be yellowish at the edges.

My question is: should I move the plants under a shade tree where they will get dappled shade pretty much all day long? Or should I leave them where they are? Thanks for your help!

[ksriramkumar]

most of the vanda's (terete/semi terete) can take full sunlight and many strap leave vanda's also can take full sunlight but care to ensure that they don't burn the leaves. I would keep the vanda's in open and observe and move in a shade net if they looked scorched.

[stateless]

that is good advice, Ksriramkumar gave, I would be concerned about the one in the glass jar because of the heat, how often are you watering them the hotter it is in summer the more I water, sometimes up to 3X a day for my vandas, but they are bare root.

[catttan]

Since your plants are not sunburned or scorched they should be OK . A general rule we use here is .that vandas should get as much light as possible without burning the leaves. They also like humidity in the 80s.

[dlbush]

Thanks everyone!

I moved the plants under the tree today because it was going to be nearly 100F (38C) and on the dry side (as dry as Alabama gets in the summer). I'll put them back under the full sun since they seemed to be doing well there. FYI they are all strap leafed.

Ed - I water my bare root vandas twice a day, before breakfast and after coming home from work. The one in the glass jar is sort of sitting on top of the jar (wired) and barely has any roots (it was a clearance shelf rescue), so I'm not too concerned about overheating it. I did move it and the potted Ascocenda to an area that gets a bit less sun, on the steps near the Catts.

Yew-Sung - I wish I could give them 80% humidity every day!!! Next goal: greenhouse!

[zainal abidin]

Watch up when you want to shift the plants under the tree to full sunlight is not really a good idea as the plants will get sunburn but under the 50% shade should be ok.

[kspalding]

I have to say yes. I would bet you a million dollars it wouldn't last a week in my yard with all the direct sun i get.

[Charlie_76]

I also had my Ascocenda Muang Thong in to much direct sunlight. I noticed that two of the leafs started yellowing and a little scorched color. I thought it could take high light and it can't. I was hoping that it would signal root production and a possible spike. But nothing as of yet.
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[leafmite]

Many orchids can take more light as long as they are introduced slowly to it. I have found that even plants that like full sun will often burn if they are taken directly from shade and put into full sun. A plant that prefers more shade may tolerate more sun if there is a constant, strong breeze or if temperatures are cooler. When I get a new plant, if I find confusion over how much light it will take, I usually just introduce it slowly to the light and watch to see how the leaves react.

[Charlie_76]

I'm not sure what sun exposure I have.. I think it's eastern. I know that my patio and my living space gets strong mid day afternoon sun. I can pretty much grow anything on my windowsill. I'm hopping that it's strong enough to grow my Ascocenda through the winter months.
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