I made the humidity trays in the attached photo. They're working pretty good, keeping the temperature around the orchids about 25 degrees less than before I made them however in mid-afternoon at the hottest part of the day my humidity meter shows it to be 16%. Other than that 2hr or so period the humidity stays about 35% on up. I'm misting all of them (these are the ones I discussed in the thread 'Rescued Mothers Day orchids') a couple of times daily at least and they all seem to be getting new leaves. They're getting watered/fed weekly or if the skewers I have inserted in them seem dry. They trays are kept full and in fact a little above the large area where the pots sit on. Anything else I can do to make these better or is this about all I can do?

So, is there water in the trays and the plants sit on top of the perfed grid?

If so, you can increase the wet surface area by adding pebbles to the lower tray.

Good idea on the perfed tray to keep the plants up above the water.

A cheap humidifier from the drug store might help you with the hottest parts of the day, too. In winter when you have the heat on at night it will be good for both the plants and you.

Good morning Elaine, you probably can't tell from the photo I posted but this tray sits upside down inside the larger one to act as a support for the top tray. Otherwise the orchids would just fall into the large tray due to the weight of the pots. I don't have any electricity to the greenhouse, yet, I'm hoping to get a generator this fall so I can put power to both of them. Oops and yes to your first question the large trays are full of water. Would it hurt if there is a bit of water on top of the perforated top tray that the orchids sit on? The reason the holes are drilled in the tray sitting upside down is of course to allow water to completely fill the large tray.

Chris, if your plants are in plastic, simply having a tiny bit of the pot touching the water should be no problem. If you are using clay, that could be a problem because the clay to constantly absorb the water. I don't know that it would but it could. You could put some pea gravel on the tray that would take care of the problem. Lowe's and Home Depot sell bags of pea gravel as well as very small bags of decorative stones.

Thanks Ken, I do have a few in clay pots but most are in the plastic pots I modified by drilling holes all around and on the bottom so water will drain. Good idea about the pea gravel, I've got several bags left over from when I made the floor of the greenhouse. I'll go out later this afternoon when there's some shade and add that to the top.

That will work, Chris. You have a purpose for that leftover pea gravel. Waste not-want not.

I just did one this afternoon Ken just to see how it would work. Took this early this evening. We'd had about a 5 minute shower about 5pm. It's so humid outside you can hardly breathe. I think the pea gravel is going to work great. I'll finish off the other five trays tomorrow. Thanks for the idea.

I like your idea on those humidity trays. One suggestion that comes to mind is mosquito control. I don't know how much of a problem they are where you live but a tray of water here is an open invitation for the skeeters to breed. Mosquito Bits sprinkled on the pebbles should help. https://www.amazon.com/dp/B0001AUF8G/

Good job!

Thanks Alice, I didn't think about mosquito's. I'll order some of the bits later this afternoon. Looks like it will only take a small amount for each tray.

Thanks Melissa, per Kens recommendation I've put pea gravel on top of the trays that the orchids sit on. Now they won't be sitting in water and they look a lot better

Here's what they look like now, a lot better I think.

They do look much more "dressed-up", Chris.

Thanks Ken, now to get my 'mosquito bits' and that should take care of everything.

chris1948 said:I made the humidity trays in the attached photo. They're working pretty good, keeping the temperature around the orchids about 25 degrees less than before I made them however in mid-afternoon at the hottest part of the day my humidity meter shows it to be 16%. Other than that 2hr or so period the humidity stays about 35% on up. I'm misting all of them (these are the ones I discussed in the thread 'Rescued Mothers Day orchids') a couple of times daily at least and they all seem to be getting new leaves. They're getting watered/fed weekly or if the skewers I have inserted in them seem dry. They trays are kept full and in fact a little above the large area where the pots sit on. Anything else I can do to make these better or is this about all I can do?

Hi Chris,you are a very manipulative person that i have to say, it is great for you to finish it. but i also have one otao room humidity monitor for my family at the range of 10-99%, and it also works as a temperature monitor from 0 to 50C.i guess you are a engineer, right

Hi Rebeca and No, not an engineer at all I just read about using humidity trays in "Orchids for Idiots" or whatever the title is. I've since modified the first ones I made and no longer use the BBQ trays. They turned out to be too flimsy in the long run. I now use the small dish tubs you can buy at Walmart for a few dollars and also some plastic louver material I found at Lowe's. Most of the louvers have been cut to fit the tubs better, some I still have to do. After I add water to the tubs I add in some algae preventative for pools and also mosquito bits.

Good job, Chris! Yes, definitely use the mosquito bits.

Thanks Carol