Leaves have a lifespan, and some leaf loss is ok. Which leaves are they? How many?

Culture sounds ok depending on the medium, but if it takes two weeks to dry out, they may not be getting enough light on a regular basis. I am cautious of west light through glass since there is often a lot of heat that goes along with it.

Well the leaves they are losing are on the smallest stalks that they have. But what I have noticed is that there seems to be some fresh leaves coming out through the dead ones. I do notice that they tend to get pretty warm leaves in the afternoons, but that's when I close the blinds all the way, but I understand what you are saying about the heat that comes through the glass. Would having a fan set up to the side of them help with the heat? Also they usually dry about in about a week, but I was reading on another website with tips for the Cattelya and the Dendrobium and they were saying that in the summer times they should be watered less often for them to thrive...is this true?
As for the medium that they are in, they are both in a bark medium. See I got these plants from my work, they swap plants out in their atrium every once in a while and they had orchids to swap out this time, so I got pretty much as many as I could. So I have a couple that are in moss and a few that are in bark.

Yes, a fan blowing across the leaves helps them stay cool even with bright sun coming thru. I have phals in a west window with a fan running across the leaves, and they do fine without burning.

New leaves coming out thru the old dead ones-- that sounds like dends to me. I've never seen catts do that. But that's a good sign for your dends.

I have two other comments:

First, sun only on the weekends isn't enough for catts and dends (maybe not enough for any orchid, but certainly not for those two types). Catts and dends need at least
several hours of sun each day.

Second, moss may be too wet a medium for your catts and dends. If you can't transplant them into a drier medium, you need to water the ones in moss less often.

The website that said keep catts and dends drier in summer--that advice seems backwards to me-- when you can give them more light, as in summer, they need more water and fertilizer. Less in *winter* when the light is less.

However, in your dark situation 5 days out of 7, it is easy to overwater. You need to increase the light so they are getting several hours each day. Make sure the medium dries quite a bit between waterings. You can use the stick method for determing dryness as described in the FAQ.

It takes a while to get the feel of what your plants need. You're on the right track. I'd increase the light *gradually*. Run a fan over them set on a timer to go on when the sun starts to hit the west windows.

Good luck.

Here in New Jersey Zone 6, I have my cattleyas and dendrobiums outside where they get very strong light and early morning sun. Since this is the main growing season, I water the bark medium very well (not sparingly) and then let the medium dry out before watering again. For regular dens, they don't want to get as dry as the cattleyas.

I agree with Mehitabel that the information you read is backwards for our area. Was it from someone in Australia? Their seasons are opposite from ours. When you read information, you must be aware of the source. People in Florida treat their plants much differently than we do in the northeast and their advice would not work for us.

Cattleyas and dendrobiums do their main growing in the spring and summer and therefore it is the time when they need the most sun, water and fertilizer (for dendrobiums, low nitrogen always). Then in the fall fertilizer is cut back, and water is reduced.

It sounds like your plants need more light and water.

Okay that sounds fair enough to me. Thanks.
I should have been more clear on the mediums the plants are in though. My dends and my catts are in a bark medium, I have 3 phalaenopsis that are in a moss medium. And what I meant to say about the light is, and I am not sure if it makes a difference (hopefully you can clarify this for me), but I have blinds on the window and I have them down and they are cracked facing downwards; so that light shines in but not the full blast.
So asking your opinion on this then, I have them on a large desk in a row...Should I move the phalaenopsis to a back row and move the dends and the catts to the front line so that they can get more light? And then gradually start opening the blinds more so that they are adjusted to getting more light?

Hopefully you guys can reply quick.

I should definitly post pics of what my set up looks like and the different plants that I have. Hopefully i can get those soon.

I did light meter readings in an ESE window and at the windowsill, the fc's were 2000 and 2' back, the fc's were around 600 fc's. There is a drastic drop off in that short of a distance.

Yes, to the catts and dens in the front row and let them help shade the phals in back. Introduce the sunlight over a week or so and then let the sun shine in on them.

Catts and dens can actually stand more fc's than the 2000 at the edge of the window so don't worry about too much sun for them.

Brooke

Thanks very much this has been so helpful!! You know I am really glad that I found this site. I was always wondering if they were getting too much sun or too little! So I am going to try making rows and see how they do!

Also, my catt is still a very baby catt (very small stalks and only a couple leave per stalk), any recommendations for it?

Thanks!

Catts only have one or two leaves, usually. They are either unifoliate or bifoliate. Yours is very normal. I treat baby catts the same as adults.

Brooke

Brooke gave you excellent advice. It sounds like you have a good plan. You can feel the leaves and if they're hot, back off the sun a bit. If they aren't, then they're okay. I have my catts right up against the glass indoors and hanging in several hours of morning sun outdoors. Some dens don't need quite as much light as the catts, but they still need lots of light.