Vanda markings
 

I bought this vanda about a month to 6 weeks ago, and although it is in FAR better condition than whats left at the shop I bought it at, it has suffered some problems:

I believe I've eradicated the spider mite it had by double dosing with Pyrethrum 5ec, 3 times, and rubbing the leaves with isopropyl alcohol 70%. It did suffer some sun bleaching as it was quarantined outside and the UK this year has been very bright, in hindsight I'd have quarantined further underneath a tree for shade. It has recieved small amounts of fertiliser, rainmix mostly and is watered every other day in the current setup with bark chips in a hanging basket, sometimes every 3 days if the bark hasn't quote dried out at the bottom, the roots on the outside of the hanging basket I planted it in are sprayed daily however, often twice.

Unfortunately, the sun bleaching and pyrethrum I think started a small bacterial browning which seems to have slowed down now, and I know it won't regain the colour of the leaves, but wondering if it is now safe to add to the rest of my collection. The brown marks aren't actually squishy or smelly at all, if I closed my eyes I couldn't tell where the brown marks start and stop. As it is starting to get colder I'm hoping to get it under proper grow lights and lessen the temperature fluctuations as I bring it inside over night, but it is still colder where it is stored/quarantined. I sprayed it with a fungicide, Provanto, but unsure if it did anything as in the UK, 'cides are generally terrible and ineffective.

I did virus tests when I recieved it and it is negative, so it doesn't have anything sinister like that.

Should I introduce it to the rest of my orchids? There is a risk to dripping water. You can also see the difference between the sides, the attached pictures were taken on the same day, they're just opposite sides of the Vanda

I think you are mostly seeing sun bleaching. I would not worry about the browning on the edges... probably just a continuation of the sun damage that the thicker parts of the leaves received . I think it should be quite safe to put with your other plants.

I would be nervous growing a Vanda in medium in such a large container with such small particle sizes. What do others think?

Vandas are much heavier feeders than almost any other orchids. Fertilize heavily every 4th to 5th watering. They hardly grow with lesser amounts.

I've been monitoring the roots and they seem fine. Its been in there for about 2 weeks now. I generally don't water until the bark absorbs moisture but give a quick spirtz of water. The roots haven't developed growing tips yet so I was considering waiting until I see some new root growth emerge before fertilising. Perhaps I should fertilise far more heavily, perhaps every water with rain mix (I have enough of the stuff to use).

As for the brown markings, I suppose really it makes sense the edges have browned and had a dieback of cells. I'll bring it through the rest of my orchids tomorrow, and hope that I have indeed got rid of the spider mite.

As long as it drains well, I think it will be OK it looks like the medium isn't very deep, most of the space is taken up by the coco mat which doesn't hold much moisture. It looks to me like it's a good compromise between what the plant wants (no medium, lots of free-flowing air and very frequent watering, high humidity) and what is practical under the circumstances.

My Vandas grow pretty well getting fertilized with everything else but they're mostly cool-growing species...growing cool, they also grow pretty slowly. The warm-growing hybrids do benefit from much heavier fertilizing.

Mine is a warm growing hybrid in almost certain of it, I'm sure its the Siriporn Pink hybrid. I'll do some double dose rainmix in the next few waterings. The coir lining is also fairly old so hold nothing really at all.

Tomorrow ill post some success stories on this forum.

I'm going to be fertilising lightly every watering, it is one of the reasons I bought rainmix.

Vanda roots aren't burned by high concentrations. Martin Motes of Motes Orchids, Vanda specialist, writes of using 20-20-20 or MSU at 1 Tablespoon (15 ml of powder) per gallon (3.78 liters) at every fifth watering.

He says proper fertilizing leads to a zone of pale green new growth at the base of the emerging leaf that is 1cm wide. If this band is narrower fertilizer should be increased. If wider than a cm, decreased.