Hi Bill!

There's a number of things that could cause this. A picture would answer some, so if you could post a pic that would be great!

For starters, you're in zone 6 just like me, so for us northerners it's very important we have fast draining soil when they are indoors. What kind of soil are you using? This seems to be the reason that most people have problems with their citrus. The soil eventually breaks down and compacts the roots. When was the last time you repotted?

Second, did you acclimate your tree to the lower light levels? If you bring a tree from the bright sun outside and put it in a room in the house without slowly acclimating it will drop its leaves.

Third, any signs of insects on your trees? Dripping sap? Small webs?

Also, what is your feeding schedule and description of environment it is in now? (Amount of light, temperature, etc.). How long has the tree been in this pot? Try to post a picture!

Looking forward to hearing more from you!

Kristopher

yeah bill..im gonna need to see a picture of this one. There arent too many images on the web of older container trees. I dont know why that is. I love seeing them. Some of mine are only about 5 years old now.

oh and I second what Kris has asked.

Leaf drop for indoor trees is typically because the leaf surface gets too hot from a sunny window and the rootzone temperature is below a level that keeps them active enough to push water up to cool and transpire.
See if the rootzone temps is above 55 degrees, that seems to be the general consensus on what to keep the roots above.

Rule of thumb for avoiding leaf drop
High light=warm roots
low light=cool roots, this can still cause drop but reported by some to be not as bad or fast.

mike

I transplanted it into a large pot 2 years ago. Used a sandy mix. It's done very well since, except several weeks after I brought it in.
I'm thinking the change of light is responsible. I do not have it directly in front of a window. Indoor temperature has been a steady 68 degrees F.
I'll post a pic as soon as I figure out how to do so. Thanks!

I have a Wahington naval orange which was doing the same thing droping its leaves. I got some valuable advice from the board here and did some changes in its enviornment.
First I changed the soil to 50% pine park and this helped a lot with the drainage. I had it on a roller and rolled it in the sun whenever we get some sun. I changed the lamp from florecent to regular one which emits some heat not much I hade sure the lamp is 12 inches away not to cook it. I fertilized it one a week with miracle grow 24-8-16. It stopped shedding leaves and I have four flowers on it now.
I think Citrus in our zones gets shocked when the environment changes from air and sun outside to get inside the house. I am wondering if green house could be the solution. I did some guesstimate that a home made green house (not a fancy one) could cost 300-400. I have three citrus trees and I am starting another three.

Thanks! I'll get some fertilizer and roll it into the morning sun. Still intend on posting a pic.