Dying wintergreen
 

I have a pot of wintergreen that was started by seed and has been
growing fine for several years. The plant is full size and was always
growing robustly (look just like the ones I have outside year round.

Over the past month the leaves have started to brown and dry up.
Sometimes, the leaves skip the brown part and just dry up. At first I
thought there maybe too much water and I held off watering. I usually
water once a week and the pot can easily drain. That didn't seem to help
so I started regular watering again.

I have not seen any insects or mold or sticky residue.

The plant has spread around in its pot and sent up new shots over the
years. It is not pot bound. In a typical scenario, a plant will look
fine and then I'll notice a leaf turn half brown. Then the leaf will dry
up and the rest of the plant will shrivel up.

I've included a link to a photo. This used to be a great looking
wintergreen. It's always sat in a west window on a bookcase.

http://ny.existingstations.com/auctions/wintergreen.JPG

Any ideas?

Thanks.

Charles