Help with sunny windows and humidity trays!
 

Now that I moved to a new place with south facing windows, I am facing some new issues.
One of the first things I did within the first couple of days was to put up a sheer curtain so that my orchids would not get sunburned. I actually shopped around a few places looking for proper sheer curtains weeks before moving. All I could find was the type that would block way too much light. I almost gave up.
Then I went to IKEA to get some book shelves, and alas! I found a perfect sheer curtain for my windows. :biggrin: super happy and relieved!

Now the main problems are high temperature and low humidity. It is still March but with the windows closed with so much light during the day, the air gets heated quite a bit reaching up to 85 already! and thus low humidity around 40.

I am thinking of getting a small fan when the weather gets hotter and hotter, but not so sure about what to do with the low humidity.
I thought about getting a humidity tray, but read somewhere that it doesn't really do much as far as increasing humidity is concerned.

So I would like to know if anyone with hot south windows ever tried humidity trays and if they seemed to work? i.e. orchids growing and flowering nicely due to the use of humidity trays as compared to plants performance when humidity trays were not used in bright hot dry window setting.

Many thanks in advance! :)

I grow in south facing windows with some of my plants. This is a built-in china cabinet. The orchids mostly sit there while blooming. I have lace curtains in front of my windows and sometimes those aren't always pulled. I do kind of a tiered system. The phrags or zygos or minicatts go right next to the window. These are usually on little wire shelves that you would use in a cabinet. Then I set paphs and phals behind those.

One thing that I have done to help with humidity, Chinese take-out food trays,then I dampened spagh moss and let that dry out. These were placed under the wire shelves and provide a little extra moisture for those plants. But I group all my plants pretty close together so all of them benefit somewhat.I really think that the moss works better than the pebbles. Just my opinion, hope it helps. Ginnibug

There's not really a good way to rise humidity with out putting up in enclosure. You can get a humidifier but you'll run into the problem of mold. 40% is not to bad... sure 60-70-80% is ideal. I grow many different type of orchid with humidity lower than what you have in the summer. You'll have to find media's that work for your conditions. I like CHC, gravel, Orchiata, and moss. All work well depending on what type of orchid your growing and pot size. Maybe experiment with Semi-hydro culture.

I agree with Keith.

By the way, putting a fan on the plants will not do anything to cool them down, as they do not perspire. That is not to say that air movement is a bad thing - it's great for the plants - but has nothing to do with cooling.

The instant idea came to me is putting some damp cloth near the plants as you organize it to your way.

Another method is use coconut fibers or husk pieces
as mulch or leave the wet husks nearby.
We got a hot climate therefor I use this way. husks will keep moistured

I use humidity trays in a south facing window and all of my plants are fine and bloom regularly. I don't necessarily attribute that to the use of humidity trays though. My RH in th winter runs around 60-70%. My thought is that it is a bit higher in that spot because I have so many plants concentrated in a small area. I think "colonies" if you will create their own small micro climate. I think if I had a single plant on a humidity tray my RH would be much lower. Ray once described humidity trays to me as "trying to raise your RH by leaving the toilet bowl uncovered."

That said most Phals are warm growers so should not mind 85 degrees at all. Mine don't seem to care one way or the other about humidity.

The bottom line with humidification is 1) enhancing evaporation, and 2) containment.

As far as enhancing evaporation is concerned, you either heat the water, giving it the energy it needs to escape the liquid phase into the vapor phase, or you increase the surface area sufficiently that the rate of escape becomes statistically significant.

A tray - even with pebbles - has a couple of hundred square inches of surface area. An atomizer turns that same volume of liquid into several million square inches of area. Which will be more effective?

Then there is containment. Nature hates a gradient. The few water molecules you pump into the air "here" wants to be spread evenly "everywhere" - and I mean everywhere in the entire atmosphere. The only reason a humidifier works in a room is because it can evaporate water at a rate that exceeds the diffusion rate of natural forces taking it away.

If you can slow down the "taking it away" part, you'll do a world of good for your plants.

Thank you for all the input, everyone.

I normally keep the windows closed and it gets pretty hot for most of the day, so I think any sort of encasing will cook them all up! lol

I think I will try moss or coconut husk as potting media. Some of mine grow in those and they seem to dry out slower. This cuts some time spent watering them all everyday, but I'm still rather concerned about the humidity level in the air, which I don't think I have much control over unfortunately.

I am thinking of buying humidity tray and fill it up with wet moss instead of pebbles.

Some of my dendrobiums are spiking now so I guess they are fine with what they get.

You can buy a humidifier or does Rays homemade one. Really the only way too boost humidity. Evaporation isn't that effective because you need a huge area for a little benefit.