Thanks for your reply Josh. All trunks are still firm. The shoot that lost the big leaves is still green inside. The pot is the original, placed in a larger pot (just for looks). The soil is your basic potting soil. Given that some of the leaves have turned brown on the ends, and the shoots were still green, the woman at the nursery thought that perhaps it wasn't getting enough water and nutrients. I have been extremely cautious with regard to over-watering, and until now, the tree has been fine. Once a month I was giving it a little Miracle Grow. My thought was that perhaps the roots were not getting enough nutrients, and I was going to re-pot to take a look, maybe score the roots and re-pot in a soil that would help retain moisture (an organic cactus mix was recommended). The plant is away from the window, receives some indirect light, and I have a plant light on it for ~6 hours per day. Thanks again!

My opinion is to leave 'well enough alone.' The plant looks fine, the leaf loss is normal. If you are careful with your watering, the mix should be okay. Just don't over-water. Your plant doesn't look sun-burned so leave it in the bright light. Use your judgment, if you think the leaves are getting burned, move it back a bit. The greyish growth is a root which is normal for this orchid. Just remember how these plants grow naturally - clinging to tree trunks, getting rained on and drying out quickly. Their roots are adapted to be in the air, not soil. If it sits in water, it will rot. When the flowers finish, it is up to you what to do. You can cut the spike off and let the plant grow new leaves over the summer (that is what I do)and then it will send a new spike in the Fall. If the old spike remains green, you might get a few more flowers, but it won't look as nice as a new spike. Please check the FAQ's on the main page of this forum for more info. These are tough plants and can take beginner treatment. You will be fine. My sincere condolences on your loss, Jane

It is a such common symptom to many big box orchids. very likely, your orchid has root rot. When these orchids were shipped from oversea, them were packed very tightly with moss. The moss are packed so tight that it cuts off air circulation to the roots. Therefore promotes root decay in a wet situation. Eventually healthy roots start to decay and leaves start to drop and plant start to die.... I have rescured many near death Phal from HD and Loew's. Common cause... root rot. What you can do is to take your orchid out of its container and look at its roots. If roots are white and healthy then you might want look for something else that casued the leave drop. A healthy plant does not drop leaves without a good reason. But if you see roots are brown and start to rot...or many times, in my expereinces, half , if not most of the roots are already rotten away. then you need to repot this orchid. You need to get some orchid mixed with bark ,moss, etc. Take away all the tight packed moss in between the roots,cut all the brown, decay roots off, leave the healthy roots alone. ...Then you repot the orchid with you new orchid soil. Leave the crown at or above the soil level. Water it and leave it in warm and filter light. if possible, mist it every morning. This is how I rescure those distrassed orchids. Yours can be save as well. it just takes time and patient.

I don't think it's over for your plant. I would pot it up into a relatively small, clay pot (4 inch diameter or so). (If you have an orchid pot--those clay pots with holes in them--that'll work too.) Use a very loose mix of sphagnum moss perhaps with some added perlite. Be sure to plant very shallowly--you don't want too much of the leaf buried. Sometimes I use pebbles as a mulch to help support a top heavy plant. Keep it in a very humid environment--mist frequently but keep the mix just moist and not wet.It should be fine and then you can decide to grow it as an epiphyte again (mounted and not in a pot).