Vanda Harkana Tkatchenko

[Ale_V]

Good morning, everyone,

About nine months ago, I bought a Vanda Harkana Tkatchenko. At the time, it was potted in sphagnum moss and bark in a pot with plenty of ventilation holes.

After blooming, I repotted it into a self-watering pot (also with lots of ventilation holes) using the same sphagnum moss and large bark. Everything was fine while it stayed on the windowsill, where it got filtered light through the curtains in the afternoon.

With winter approaching, I moved it to my greenhouse, worried that the dry air from the heating (humidity dropping to 40%) and the low light levels might harm it. It’s been there for three months now. Unfortunately, I’ve realized that the situation has worsened considerably. While the leaves are growing faster, many roots have died.

In the greenhouse, the humidity is at 90%, and the plant receives about 3.46 DLI of light (12h @ 80 µmol/s/m²).

Since I can’t manage fully aerial roots due to the watering frequency required, what are my options?

Additionally, if 40% humidity is acceptable (temperature goes from 22C maximum to 14,5 minimum at night), I’ve now set up a grow light on the original windowsill. I could provide even more light there, specifically 10.76 DLI at the point of highest intensity. What do you recommend?

Thank you very much!

[Ray]

Two comments:

In my experience, vandas do best when they have a full root system hanging below them. You say you cannot handle the watering with such a method, yet you said in another thread that watering for mounted plants would be no issue, so I’m a bit confused.

Second, I think your greenhouse conditions are entirely too cold for a vanda. 22C would be close to the lowest nighttime temperature the plant should experience, not the highest. 30C or higher is more normal.

[Ale_V]

Thanks for the feedback!

I’d love to hang up the Vanda, but I don’t think I have enough vertical space in my greenhouse (which is just a small room, 2m x 1.3m). It’s already packed with other plants, and there’s a shelf limiting the height. So, the trunk project will have to be outside the greenhouse.

As for watering, I imagined using a system that sprays water directly onto the roots (and the wood). The water would then drip off the wood and into a support I’d build to catch it. But if I were to hang the Vanda, spraying it would create a mess since there’s no wood backing to control the water, and I’d still need a solution for collecting the water dripping off the roots.

One idea might be to attach it to a piece of bark (I found two pieces of conifer bark on the ground—they seem thick enough to hold up for a while). That way, I could spray it, and the bark would act as a “shield” to prevent water from going everywhere.

The big issue is still finding a place to hang it: I might attach it the red spot I've marked in the picture, but it would be very close to the light (between 11,20 and 15,40 DLI - being so close a small difference in distance makes a great difference in light intensity). Even inside the greenhouse it’s already cold, and outside it’s worse, with temperatures ranging from 20°C during the day to 14.5°C at night.



I’m attaching two charts showing the temperature and humidity for both locations (greenhouse and the outdoor windowsill with the orchids).

Window:


Green House:

[Ray]

For water control, you just need to get creative. A piece if thin plastic sheet behind the vanda could collect and direct spray downward. A plastic tray ought to be able to collect it.

Another alternative is a tubing system with a tiny spray head or two tucked within the roots.

I still think you're going have a very difficult time keeping the vanda happy with those temperatures. They are heat loving creatures.

[estación seca]

Yes, 15C is much too cold.

[Ale_V]

Ok, for hanging the Vanda, I'll try!
Is the bark any good? I would prefer a more natural setting than a piece of plastic..!
Otherwise, to hang it just with a metal string, can I simply wrap the plant with it?

Also, I have 15C outside the green house, in the green house I have 23C during the day and 20,5C during the night, as for the graph attached.
It might not be the best but it's the best I can do (there is no heating inside this little room and outside it's freezing cold in northern italy at the moment!).

[estación seca]

Is your home warmer? Warmth is much more important than humidity in winter.

[Ale_V]

More or less is the same everywhere.
I have this little greenhouse at my studio (and it is the warmest place ranging from 23C to 20,5C day/night), the studio room temperature is more or less the same as at my house unfortunately (22C to 14,5C day/night).

[Ale_V]

Unfortunately, today I took my Vanda out of the pot, and the situation is much worse than I had anticipated. There are very few roots, and all the ones it grew this summer have rotted. I have cut everything that seemed rotten but I've left all the roots that, even if brown, were still totally stiff. Despite everything, the new leaf seems to be continuing to grow over the past few days.
I have hung the Vanda on a piece of wood, and now I am working on an automatic irrigation system.

Is the situation already hopeless, or is there still a chance to save it with the right care?

Thank you so much!

[estación seca]

This is probably because of cool temperatures, but there are still roots. Even during cool periods and with few roots bare-root Vandas should have the roots wet every day, unless they are still moist from the previous soaking. They should continue receiving fertilizer. This plant is able to take up both water and fertlizer, and it needs both.

Heat water to about 37C. Soak just the roots in that, long enough for them to become dark green and wet. I don't know what kinds of fertilizer you have, but I would use a full dose every 5th watering.

Keep the plant as warm as possible.

If you have access to Kelpak kelp root stimulant, I would use that according to the label directions.