Oncidium dries out every night

[Mercurianmad]

Hey guys. I had to turn down my humidifiers to keep them from creating condensation on my windows at night, so I’m pretty sure humidity levels in my house are now 45-50%. I turn them up more in the sunny day when the heat can evaporate the moisture in the windows.

So I’ve got a fan running near my orchids all the time to give them good airflow, and my oncidium orchid, which is potted in lava rock because it didn’t like the fir bark mix, is drying out every night. I have to water it every day now. Is this ok for it? These periods of drying out. I’m pretty sure it only has two healthy roots, including the air root. Here’s some pics of my sad plant. I’m
Hoping it will improve in time, as it’s able to grow more roots.

[Mercurianmad]

In this pic you can see the fan behind the piano. This oncidium seems to need more humidity than my phals do. I’ve had to keep them on separate windowsills just because when they were in the path of that big humidifier they were getting those edema spots. Moving the fan closer seems to have helped but now I’m worried it’s drying out that oncidium too much. Lol. I wish I could afford a greenhouse.

[aliceinwl]

Maybe try to source some smaller grade lava rock so that it holds moisture longer?

[Ray]

50% RH is fine.

Turn off the fan. The idea behind air movement is to prevent pockets of stagnant air. In your home, with that much space between the plants, there is unlikely to be any.

Your plant is very desiccated. What is the condition of the "subterranean" root? Probably insufficient to take up water.

I recommend you consider something like THIS.

[Mercurianmad]

Thank you for the advice. Yes the bottom root is pretty bad. I actually have soaked the plant in kelp max and watered twice but I was nervous to put the bag over it, I didn’t want it to rot. Do you think a gallon sized bag would work?

[Ray]

Originally Posted by Mercurianmad

Thank you for the advice. Yes the bottom root is pretty bad. I actually have soaked the plant in kelp max and watered twice but I was nervous to put the bag over it, I didn’t want it to rot. Do you think a gallon sized bag would work?

The idea is to trap humidity, but you want to put the bag in place when the thing has been watered, but the plant itself is dry. The bag should be big enough to cover the plant and pot, while remaining unsealed.

Keeping it VERY warm is also important, as it stimulates growth. Bottom heat, such as setting the pot on a seedling heat mat, is also excellent.

[ghuylar]

In my climate, my potting media also dries out very quickly. For the orchids that prefer completely drying out for periods this is okay, but for my oncidiums who love water I have potted in 100% sphagnum moss. It retains moisture for longer than bark or lava rock, allowing me to water less frequently. If you have the right climate and know how to work with it, sphagnum moss is amazing! Just allow the moss to get just crispy or almost crispy between watering, and I have found that is a good level of moisture, without letting the media get overly soggy.

[SouthPark]

MM ....... if you have access to smaller pieces of scoria/lava rock ...... then you could use smaller pieces, which might hold more moisture for longer.

I use smaller pieces for some of my orchids (like phragmipedium, and some juvenile paphiopedilum, and some juvenile oncidium, and also my mini phalaenopsis).

The links below show my mini phalaenopsis in small piece lava rock (scoria). The extra images show regions where I aim the water (with my garden pump-action weed sprayer watering nozzle, not used for spraying weeds though haha). The idea is to just focus most of the water in a band of your own choice near the rim, or the outer part of the media, just to avoid getting too much water into any big clumps of roots (which could well develop later) directly under the orchid.

This method of watering could work nicely for you too.

Also - don't worry about dry-out. The roots can definitely handle limited periods of dry out. My juvenile oncidiums have their roots dry out every day too. It doesn't harm them at all. My phrags and paphs handle dry out too - no problem as well.

Pic 1

Pic 2

Pic 3

My juvenile oncidiums are potted in the same size small scoria pieces. Although, I also happen to have a medium size oncidium potted in 10 to 15 mm diameter scoria pieces (much larger pieces), which is growing very nicely too.

[Cym Ladye]

Suggestion posted under wrong thread.