Vanda yellow spot on leaf

[Mercurianmad]

Hi guys. When I got my new vanda earlier this week it had a yellow spot on it. Now the spot has gone brown. The nursery I got it from said it was from the high light on Hawaii. They also said that it wouldn’t harm the plant. Now the spot is going brown so I’m wondering if that is accurate? The first attachment is from the day I received it. The second picture is from today. Thanks!

[Roberta]

It looks like sunburn to me. The damage probably recent and still developing when you got it. It won't harm the plant - not a disease. You could clip off the damaged part if you hate looking at it, but it does the plant no harm. And the leaf still has green at the tip so is capable of photosynthesis, so leaving it could even benefit the plant. If it spreads beyond the original area it could indicate a different problem, but so far it just looks like it is staying where it was.

[Mercurianmad]

I just wish I knew if I was giving these plants enough light. My grow lights coming tomorrow and I am going to start out just on the softest dilution of light from one of the three lights and work my way up every week I guess. I just don’t wanna burn it especially since the vanda already has that huge sunburn Spot and two of the leaves its leaves are getting this blackish purpleish color on them. I’m pretty sure that’s just because it has black purple flowers but I can’t tell whether it is at the top of its light intensity now or whether it was at the top of its light intensity before it got to me.

[estación seca]

Most Vandas (and Cattleyas, your other plant I think) are deep green when they're getting insufficient light. With proper light they are a very light green, perhaps even with a tinge of yellow. There are a few Vandas that are normally lighter green than most other Vandas.

I don't think you could burn Vanda leaves with any LED grow lights sold for home use. Too close to the transformers and the heat might damage leaves, but I doubt light intensity would ever do it.

Even in bright sun, a fan on a Vanda will usually keep leaves from scorching. I tested this here in Arizona - even on 104 F / 40C days, putting a fan on seedlings outside in full sun kept them from scorching. If you have any concerns in your home, put a fan on the plant. It will dry out faster and need more water.

Remember a plant that has been in lower-light conditions for a while will need to be accustomed to high sunlight gradually, not in one jump. This is a perennial spring issue for people who need to bring plants in for the winter.

[Roberta]

Vandas are high light plants. What may have happened is that it got a blast from direct sun. Normally, even the brightest light is diffused a bit by shade cloth or trees. But even the toughest plant can get sunburned with a lot of local heat. So you need lots of light, but it also needs to be accompanied by enough air movement so that there's not a local hot spot. You can test your arrangement by touching the leaves... if hot to the touch, then back off. You want light, not high heat. (Vandas can be very happy with temperatures above 100 deg F, especially with humidity and air movement. But you would not want leaf temperatures of 130 deg F... like in a hot car.) In fact, the hot-car concept can be applied here... you're OK outside even on a hot day, but don't leave children, pets, or plants in the car with the windows rolled up.

[Mercurianmad]

Great thank you both. Yeah our outside temps this past week have been 103. Inside it’s 75 but next to the window it’s gettin to be about 78. Fingers crossed my husband is going to be building me a large, 300 or so gallon orchidarium. Knowing how busy he is though he might not build it until fall so I’m just keeping them as happy as I can until then.

The oncidium I have needs less light than these guys right? I only ask cause it’s on the same shelf as the vanda and the cattalya.

---------- Post added at 01:27 PM ---------- Previous post was at 01:26 PM ----------

How long do you guys think these will take to bloom? I’m used to dealing with rescue orchids, and they take a year or so to bloom after I get them just because they’re in such rough shape. But these are healthy plants so I’m hoping I’ll see some blooms this year.

[estación seca]

Most people with a sunny window don't need an orchid terrarium to flower Cattleyas, nor Oncidiums. An exception would be if you have sun blocking glass, which removes a lot of the light plants need.

Vandas can do well in a window inside a house but it is difficult keeping up with the watering. A lot of people growing them in the house keep them in pots or baskets with medium bark, or something of similar chunk size. This retains water around the roots for a little longer than when bare-root. The higher humidity in a terrarium makes it easier to water enough, and they appreciate higher humidity for growing. But most will flower on a windowsill. In a terrarium they need supplemental electric light; you can't put a terrarium in sunshine, or it will cook the plants inside.

Vandas and Cattleyas are among the orchids needing the most light. Oncidium hybrids need a lot less. The Cattleya and Vanda would probably be happy in that sunny window so long as the sun doesn't heat and burn the leaves. A fan would prevent this. The Oncidium doesn't need the sun falling directly on its leaves, but it will tolerate that.

The Vanda should not go below 55 F/13C in winter. The Cattleya and Oncidium would be fine down into the mid 40s F / 6-8C. In summer none of them would mind your house temperatures. The Vanda might grow a little faster if it were warmer. It could probably spend summers outdoors in dappled sun under a tree or on a patio with a slat roof if you can keep it watered enough.

Your Vanda is not big enough to flower. It could be flowering size with 2-4 years of excellent growing.

If the Oncidium is a plant that previously flowered, it should bloom with each new growth if cared for properly. Many of them make 3-4 new growth cycles per year in warm climates like yours.

The Cattleya I see in the background might be big enough to flower on the next growth, or it might need another year or two. It would depend on the ancestry. Some hybrids make multiple growths per year, and flower 2 or more times. Others flower once per year.

[Roberta]

Oncidiums definitely want less light than a Vanda. The Vanda and Catt probably similar, though depending on which one, the Vanda probably could use more.

The outside temps for the Vanda should be fine, as long as there's a breeze and/or some shading from trees. In fact, if the nights are staying reasonable (like above 65 deg F or so) outside would be best for the Vanda. Remember, these come from tropical areas. Your biggest challenge with it is humidity/moisture. If it is outside, it can just be hosed down a couple of times a day (rather inconvenient - and messy -to to do that in the house)