Is it turning brown and mushy, or drying out & yellow? If it's the first it's a bacterial infection and I would suggest removing the leaf, if it's just turning yellow that means the plant is using it up for nutrients. It's normal for the oldest leaf to die off, but usually not when the plant only has 3 leaves. Sounds to me like it could use a little more light (be careful not to burn it), so that it has more energy to support the blooms.
~Jem

Without knowing what type of orchid you are talking about (I assume its a Phal), its probably normal die-off. The plant may be making a new leaf and losing an old one.

its a phal, dont see any new leaf buds but sounds like a good theory as light doesnt seem to make it any better, just hoping the 2 remaining leaves can provide enough life support for the rest of the plant - should i fertilize?

Do you have a photo? Without seeing how its planted I really can't advise. Forget the 'soil tea' and just get a fertilizer and give it a small dose and see if it begins to make new growth.

I see you mentioned a 5" pot. That should be fine unless for a plant with only 2 leaves. Increase the light and give some fertilizer and wait. Don't do anything drastic. It should start growing.

Jane

Can't be certain what is going on with your particular plant, but normal leaf loss in phals starts from the tip and works its way toward the stem.

Leaf loss that signals trouble starts at the stem.

A 5" pot is not too small, except for the biggest, honking godzilla phals. OTOH, 5" could be too big. Watering once a week could be okay, or could be too often. You need to balance water with air movement and light-- more light, more air movement, more water. Less light and less air movement, less water. Don't water until the pot *feels light*.

If the other leaves stay turgid you are okay. If they start to get flaccid, you need to check the roots, see if it needs a smaller pot.

This isn't exactly a follow-up to leaf turning brown. We transport our orchids from Florida to northern IL each year. When we got to Kentucky we put them all outside our motorhome and one day the sun was waaaaaay too bright and one of my phals got totally sunburned. Of course, the leaves have disintegrated and now it has no leaves at all. The roots in the bark look healthy. Is there any chance it will generate new leaf growth? Or should I just give it a nice burial and try not to do that again.

NitaM in Seneca, IL

NitaM, I would recommend trying not do it again whether this phal recovers or not :)

It's possible that your phal will grow a basal keikei and eventually recover. Be careful that you don't overwater since the plant has no leaves to supply the water to. However, even if this happens, it will take quite some time for the plant to recover. If you have the space and the patience to nurture this plant, keep it. Otherwise go and buy yourself a new plant.
~Jem

It's not a good idea to use soil tea from the garden as you don't know what kind of pathogens you're introducing to the plant. Outdoors the plants can fend for themselves because it's a totally different environment. The plants grown indoors are a bit more delicate and easily infected. Orchids grow slowly and you won't see any changes in a day or two. Maybe even a couple of weeks. But you've gotten some good advice here.

JEMSTA - thanks. Well, I'll probably just let it hang out with all the other phals and see what happens. If nothing by the time we go back to FL in the fall, it'll get the heave-ho.

Well, I have a "similar" problem with my Den., the bottom leaves are all turning yellow and dropping. I do have a new cane and a flower stalk growing. It gets a lot of diffused light from my living room window.I did notice that some of the yellow leaves are sticky with some kind of clear "drops". Maybe it's a "pest".
I'd appreciate any help!!!

Annamaria