Vanda fungus?
 

I currently have three vandas living on a tree outside in my yard. Until recently they've been rather happy. One still is and has a bloom spike on its way..

The other two, however, are have some (to me) unidentified nastiness on them. On the one it looks like a fungus... on the other it looks like some sort of leaf rot. I'd love help identifying the problem and getting a possible solution.

These are outdoor plants so I can't add less water to them, only more. Until recently it has been pretty dry around here so I have been misting the roots twice daily, careful not to get and let water sit on the leaves...

http://www.orchidboard.com/community...s/img_0319.jpg

http://www.orchidboard.com/community...s/img_0316.jpg

:bump:

I am no expert on disease, but I do grow a mean Vanda. I think the dark discoloration is tanin from the oaks. That one oak leaf in the pic shows a dead "oak tea leaf".It settles into the leaves and leaks out to stain the plant. I have one that came from a grower with bad water. My stains look like a toilet bowl with lime stains. It's whitish instead of dark like yours.
The pic with the black spot is another matter. Cut that leaf off as best you can and use cinnamon on the wound. Normally, this kind of thing could be ignored if the plant is currently vigorously growing otherwise. Use a hose to water them in the summer. Soak them when it is hot. The heat of the day will dry them well enough. And make sure they get enough sun. Vandas like sun, but introduce slowly. The leaves should be the "right green". This indicates proper light.
PS. The one black spot on the bottom leaf may also be from heat damage or trauma. You may want to simply watch for a spreading effect. If it spreads, cut.

Charles - Thank you for your reply. In the days since I posted these pictures the dark spot has not grown and, in fact, I've noticed a bloom spike popping up! I'm thinking now that maybe it is some sort of trauma.

Yeah. When the roots are growing and the plant is spiking, sometimes what looks ugly is only a bruise.
Get us some pics when it blooms.:)

Looks like dehydration and sunburn. Most but not all Vandas like warm temps and bright but not direct sun light during the hotest part of the day ( noon to 3PM). Misting Vandas is nice, but doesn't do much for them they love to be drenched in water. In the summer that may mean watering everyday. Just don't drench them at night. Active growing roots have a silvery sheen/velum. If you water them enought the roots will turn greenish. It is almost impossible to over water a Vanda during the summer if it is in an open basket with little media.

:waving I agree with Uechi, probably due to sun and not enough water. I have about 10 vandas outside (Ft Lauderdale) and I have that on several plants on the older growth. I just ignore it or cut that leaf off if it is low enough. If it is a high leaf I just turn the plant so I don't have to look at it. It is just unsightly but nothing bad in my experience :twocents: . I have gotten vandas from Motes with that "burning" on it so even the experts can't prevent it sometimes. It is just so hot and the sun so intense here. Until the rainy season gets started, I water them every day. Really soak them with the hose. I don't grow mine in any media so I can't really overwater. Here are some pics of the same thing on some of my plants. :photo:

I will up the watering, but the root growth is really good. In fact they have been root crazy for the past few weeks. I assumed that if the root growth was good and I had new leaves forming that I was watering often enough. However, as you point out it's hard to over water a vanda in no medium.

Thanks for all the advice!

I have a couple of vandas on trees outside and I have had that black stain pop up too. When it bothers me I just wipe it off Im sure they sell something for hat but even a wet paper towel takes some of it off.I bet a sponge would work too. Is anyone cringing yet? LOL

That black stain is most likely sooty mold which is harmless.