I haven't done it with an orchid yet (just got mine a matter of weeks ago) but with African Violets, during the winter, I would sit a tray with pebbles on top of the radiator in my living room, and keep water just below the top of the pebbles. They did great that way, blooming constantly.

Lynn

If you purchase one of those humidity gadgets and take readings around your home you will find that the trays do not do much in raising humidity levels.
A small glass-house jammed with plants works much better if the door is closed.
Anyway, i think all this tropical/ humidity stuff leads many a new grower astray.
The room where i'm typing this has a 600 litre heated fish tank. Even with the door closed the humidity leaks out into the rest of the house. Just as well it doesn't work as many imagine humidity trays do, because there would be green mold on the walls.

TillyGrower,
I think they are useless, messy, and probably only offer humidity just above the water. Better to buy a Vicks brand "Vaporizer" humidifier. Low cost, easy to use and lots of humidity.

Totally useless in my opinion. A humidifier would be much better, as tolu says.

I'm glad to hear that my supposition that humidity trays are useless is probably correct.

Interestingly, this is what the American Orchid Socety says about it on their website:

"Humidity is important to phalaenopsis... In the home, set the plants on trays of gravel, partially filled with water, so that the pots never sit in water."

:-)

The cheap vaporizers work the best. They are small and you can put a few around your room. I would group your plants together on tables and place the vaporizer nearby. They do work but in winter, you wind up having to fill them every few hours.

Orchids will survive the low humidity for a few months until they can go out in spring.

In this shot you can see a steam vaporizer on the floor on an egg crate.
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Jane

Would you talk about the supplemental lighting you use, Jane?

I disagree about the use of humidity trays. I think they do help a bit in a couple of ways:

1. They do release a little humidity, especially if kept wet.
2. They tend to force us to crowd plants, which aids in humidity.
3. And best, they make watering easier by allowing me to water in place.

My orchid growing room (spare bedroom) is usually 10-15% higher in humidity than the rest of the house in winter, but then I have 15 'pebble' trays in there also.

Your mileage may vary,

Bob

I mist my plants in the morning once a day. I've been doing that for many years and they thrive. All you need is a cheap spray bottle from the dollar store. Once a week I take my orchids to my sink and give them a good watering with the spray hose. (except for when I fertilize them) I use Luke warm water and again I do this in the morning.

I have a humidity tray for one of my orchids with a few other plants crowded around it. I usually mist my plant in the morning. Another thing I do to help with humidity is when I'm waiting for tea to cool down or steep in the morning, I set the cup next to my orchid so the steam can humidify my plant for a short time.

The science doesn't bare out the success of humidity trays. The hunidity , because its a gas, spreads throughout the house as gas is wont to fo. it doesnt stay localized around the plants. Jane is right, they will be fine in low humidity until they go out in the sprig. Most of these plants are hardier than people give them credit for. Frankly for most of the plants we how humidity really shouldn't be a super serious concern. I don't give it a second thought for my plants. If you are really concerned you can get yourself an orchidarium.

As i said above, the trays do not work to the degree that many people think they do and "just as well" because if they did this room would have mold on the walls.
I am using the 600 litre heated tropical fish tank to keep my small Phal collection warm.
Some readings. Midwinter here at 14.00 hours Brrrrr
Outside at nearby AWS 16.5C 39% humidity.
This room 17.3C 44% humidity
Adjacent room 14.4C 46% humidity
Upstairs room 16.6C 51% humidity
Glasshouse with door open watered about 1hour ago
17C 60% humidity.
As Terp says the "water" gas spreads and tries to equalise everywhere. If the arid westerly wind is blowing it tends to be arid everywhere, whereas if the wind is coming from the Pacific Ocean the humidity levels will rise everywhere.
This humidity business leads to overwatering and death of orchids. Many orchids are adapted to survive some dryness.
I only watered today because the plants needed it, not because the air is dry.

I will add that there is absolutely nothing wrong with using the trays to catch water. It could be an attractive water tray if done properly. That's about all they are good for though.

It has been proven that humidity tray are ineffectual. The evaporation of water into the atmosphere, especially in an open area is negligible. In a semi-enclosed environment like a greenhouse, then watering down the floors and walkways will increase humidity. In a rather dry indoor environment, not much at all. The use of a humidifier is preferred. Also semi-enclosing the growing area with plastic can help keep in the humidity. Always provide fans for adequate air movement. Humidity is "bad" only when temperatures are too low and lack of good air movement (botrytis). Cattleyas can stand a bit lower humidity, but phalaenopsis, miltoniopsis, odontoglossums, paphs require higher humidity, (and varying temperatures...odonts, phragmipedilums, miltoniopsis require moist, cooler well-circulated air. Phals require warmer temperatures as warm-growing paphs.

I made some measurements with a digital hygrometer on a bucket of water in my apartment at 40% RH, 23degC. Inside the bucket, humidity increase by 3-4 percentage units i e almost negligible. One inch above the bucket, no effect at all. So for increasing air humidity in a living area, all things like humidity trays, pebble trays and aquariums don't work, the ventilation removes the moist too efficiently. Unless you create a humidity tray so big it is a bit taller than the plant... :-) and even then the effect is very small.

However, a big aquarium (or pebble tray or bucket of water) can be as efficient in humidifying air as a "humidifying machine" if big enough. What I'm saying is that even if you buy an electrical gadget called humidifier, it won't increase air humidity any better. Neither will grouping plants together. Get a hygrometer and you will see.

All of these conclusions are for living areas. Which must have some ventilation otherwise you (and your plants) wouldn't like being there. On the other hand, all of these things do have an effect on the air humidity in confined spaces. E g if you want higher humidity when you sleep, you can shut off ventilation for that room and shut the door, and a humidifier or aquarium will help. (For that reason, I'm thinking that perhaps I'll try shutting of ventilation for a day or two in the winter and increase humidity i e by boiling some water on my stove, since the really low indoors humidity is when temp outside is much lower.)

Misting also has a very small effect on air humidity since it is wet only for minutes and there's not more increase in air humidity than with the other methods.

One thing I wish I could get some reliable data on though, is if perhaps misting has a positive effect on humidity loving plants because of the water on the leaves, i e a direct effect because of the water. not the indirect effect of possible air humidity. Since a week back I'm trying out misting most of my plants (not succulents) thoroughly (until water drips of them) once every morning. If it helps or not I can not say yet, and unless I try it on one of two identical plants I might never be sure.

If anyone has experience in trying both with and without misting, it'd be interesting to hear about it. And more than once per day I can't be bothered to do it. :-/

The question is....how much humidity is needed, and there do not seem to be many answers.
I suspect not much in the case of Phalaenopsis, but there is no data so it is all trial and error in your conditions.
As for "Humidity Loving" I think that refers to orchids that grow in nature in cloud forests and perhaps they should be avoided in Home culture. Though perhaps some of the miniature types would do well in a terrarium.
What happens indoors in winter where the outdoor temperatures are very low? Is there some way that cold air from outside has some water added as it is warmed inside?

What if you use a clay or Terra cotta pot. Mine absorb the moisture and keep the inside humid. But they never dry out if I keep filling the tray, how do I water it if its always moist?

There's a pretty cool new invention called an aqua stone. I don't know if it's any better than a humidity tray but it looks cool. It's one of those "as seen on TV" things. I got a few at Walgreen's. It's kind of like a ceramic ball that sits in a bowl of water.

The trays are good for catching overflow. Nothing more. Pile the plants close together for the winter. They give each other a small micro-climate. Put other house plants close by.

Somehow, they do survive the winter and the dry air. Get them outside in the late Spring. Never had a orchid die in the winter due to dryness.

Jane

@tamela_starr I am a new orchid owner, but grew up with a mom with shelves of African violets. She used panty hose wicks that ran from plant through drain hole down to a lidded cool whip type container filled with water. The shelves had fluorescent lights. Quite a business. On to orchids. I did read, as you said, to place your orchid in the kitchen sink and water weekly. I had also remembered seeing someone must their orchids with a spray bottle so I have done both of these . just worry about the hygrometer thing. New mom ha ha.

If you must mist, do so in the early morning so the the orchid(s) dry during the day. Using that method you are, I suppose, copying nature. (Dew)

But if you have a Phalaenopsis compare those thick water storing leaves with the leaves of African Violets.

If you a new orchid mum. a cheap temperature humidity gadget might be a good investment.

I've only been an orchid addict for about 3 years - mainly have phals, a dendrobium, a vanda and now 2 cattalyea's. I live in Zone 5 (PA) and my phals and den rebloom with many large blooms every year. They sit on or near my window sills and I do not add any humidity, though I do have them grouped, so that may help. I also (due to fear of bugs/aphids) do not put them outside for the summer.

Maybe I've just been lucky - but, I also do not mist - unless I just mist the aerial roots. I'm afriad I'd get crown rot.

This coming winter, I may add a vaporizer to see if it makes a difference.

Maybe humidity for what I'm growing isn't truly necessary, maybe they just adapt to the growing conditions.

New orchid mum, only got one at the moment, if i don't kill it then I will get more, if i regularly use my steam iron in the room where my orchid is, would that be beneficial as regards humidity?

No. You will need a humidifier or humidity tray to significantly increase humidity.

I had one lonely Phal in my last duplex, super market special, bought with one spike only. Prior to my move, it received a huge amount of light, including direct (east/south), heat and humidity. It rewarded me with two spikes last year. She along with two other new additions are sitting in an east facing window sill with about 2 hours direct morning light and supplemental humidity. Wonder what they will do now??

Don't worry about humidity. Where do you live? Need to give more info.

Two hours of direct sun is fine as long as the window is bright during the rest of the day. Give a cool down in the fall. That is important to get spiking.

Jane

I live in Montreal, Quebec Canada. Very cold and long winters. We are still in heating mode. Apart from the 2 - 21/2 hours of direct sun, the window is moderately bright, for the rest of the day.

When I grew in NY, I always gave my Phals a 'winter coat.' I would soak sphag and lay a layer on the surface of the potting mix. It would hold moisture and keep the roots from drying out. In spring I removed it.

When the plants have aerial roots nothing helps, not even misting. I did use vaporizers nearby for certain plants but honestly, I never noticed a difference. I think the plants can get through the dry winter and begin their new growth in spring.

I wouldn't worry about it. As long as the plants have bright light they should be fine.

Jane