I have orchid moss, and I need to extend the times between watering of my orchids. Can cattleya take being potted in moss as long as I don't overwater?

Yes they can, commercial growers use sphagnum all the time to grow Catts.
But it's a difficult balancing act...I would suggest that you leave them as is if they are in a bark mix and water REALLY well when you can, they don't mind drying out.

Thanks Lindsey! Mine are from Hawaii so I understand why they're in bark. But it's not so humid here. I end up watering every 3-4 days, which is going to be challenging in the next month or so. I was hoping to extend it to every 7 days. But maybe now is not the time to try that.

Melissa,
I grow almost exclusively in clay pots, in Florida where we have a bit of humidity. I pretty much grow only Cattleya. Unless there is some extreme weather ( like the past 2 weeks of low humidity, high winds and near 100 degrees) I generally only water once a week. I water throughly , back and forth a few times. There have been more than a few times where I was out of town for a month or more and the plants only got watered twice. They all survived and bloom for me just fine with this treatment. I should think your plants will be fine as well.

It sounds like you are watering too much already. How big are the pots that the Cattleyas are in?
If you do not have experience growing in moss, I can almost guarantee trouble for you if you go the route. If my Cattleyas are in 6" clay pots, depending upon light and season, I water once a week to once every ten days.

If your Cattleyas are really hydrated, you have been watering on schedule, I can see them going two weeks easily between waterings. They will not suffer that much that quickly.

Part of the problem is we have low humidity in our house.

How about dendrobiums? They're a little more water loving, aren't they?

Depends upon the type of Dendrobium. Latourias yes, Dendrobium phalaenopsis no.

Melissa, If you HAVE to grow in your house, I would suggest something other than Cattleya. They generally need much more sun to develop buds and bloom than most houses can provide. I used to put my Catts. outside on a bench in the summer and they were as happy as can be. I put them out in a protected area and gradually moved them to more sun, they stayed out until the night time temps were in the low 50's

Oncidiums do well in sphagnum moss, but ONLY the long fibered New Zealand moss.
Smaller African species like Jumella and Angraecum do well.
Madevallias, Draculas and smaller Maxillarias do well.
Pluerothallis and their relatives do well also.

Neofinetia/Vanda falcata is traditionally grown in long fibered Sphagnum. This specific Sphagnum root-wrap is a bit of an art practiced by devoted Neofinetia growers. But, this is done in the Spring and usually removed in the Fall when the plants enter their dormant phase.
It should be mentioned that old Sphagnum/old = older than 6 months, starts killing the Neofinetia roots.

I have always found Oncidium alliance orchids quite water needy, so growing them in sphagnum moss does them well.

I use long fiber moss, with the Vandaceous orchids , both indoors & when put outside.
I just pack it fairly well, inside the basket & when roots get longer, just drape it, so it hangs over the sides of the slatted wood, hanging baskets.
I've also seen, some Dendrobium, in plastic pots filled with lava rocks, before & kept inside a sort of plastic style bag, that helps keep it humid, inside that bag, sort of tied nearly closed, at the base of the plant.

One thing I should mention if you keep your Orchids outside, birds love Sphagnum for nest building......for sure in my neighborhood....

with Ursula. They also love that Spanish moss for nests.

Wonderful! This is just fabulous information, thank you so much!

Yes I do have to grow in the house but I've had them under lights. So between that and low humidity its challenging.

The phals that are just in bark, I've noticed the roots shriveling if I don't water every 3-4 days while they're flowering, which is what started the 3-4 day orchid checks. I've been watering the others when their pot feels too light. Sometimes it's 3-4 days, other times it's longer.

One of my phals has 27 blooms and counting. The others (dendrobium, cattleya, and Paph) have not flowered since April. But I think that's normal. Oncidium has not bloomed in the last year, for some reason. The Zygopetalum just finished blooming two times in a row.

# 1 reason an orchid, that has bloomed before, does not bloom is improper light!
Once you correct that and it still doesn't bloom, you look at water, temperature, fertilizer, media, pot, etc.

Well Bill, it CAN'T be my fault it's not flowering.....

Now that I really think about it, the media is probably the real issue with the oncidium.