Why is my white angel trumpet tree dying. E-mail address is wvnancylee@hotmail.com

I'm not sure what kind of plant an Angel Trumpet Tree is; maybe a brugmansia?
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I don't know much about them, but according to this website, losing the leaves in fall is normal.

I hope it does okay; I really like the smell of them and am planning on growing a bunch of look-alike daturas next summer.

Here is a link that might be useful: Brugmansia care

Aren't brugs annual here? My dats have all croaked.

Brugmansias can be propagated by cuttings.

But with a sizable tree, a good way to go is to strip off any remaining leaves just before frost and place the pot in a cool dark spot for the winter, where it can stay dormant in frost-free conditions (40-45 degrees is optimal). Water every once in a while to keep the soil ball from completely drying out.
Since your tree has already dropped its leaves, you can just set it in a cool place for the winter. A garage would also work if it doesn't freeze in there.

I always had problems with mites on them in the spring.

I kept mine in the garage this winter. I think it got too cold this year though. we will see.

these are gorgeous plants, but they are supposed to be highly toxic to dogs. we were going to buy a huge, gorgeous one at home depot when I checked to see if they were poisonoust to animals. they will kill a dog if ingested.

First, yes, that is a Brugmansia...unmistakable. Second, dropping its leaves is a good thing, as pests can be prolific when a plant is brought indoors where natural predators are generally discouraged. Without leaves, most pest insects will have no source of food to encourage remaining on the plant. If you do want to bring plants in for the winter, but also wish to retain foliage, consider removing soil from the root ball with the gentle spray of a garden hose, then repotting in soil which has had limited exposure to the outdoors, or has been sterilized in the oven at a low temp. Most indoor insect problems begin by bringing in insect eggs which are in the soil. There are no guarantees that this will work, but I personally would like to reduce the chances when it comes to bug infestations in my house. Third, reduce the waterings and eliminate all fertilization for the cold months to sustain the plants dormancy. Gradually increase watering and resume light feeding in the spring to draw out the years first leaves. Check out the link I have provided for more information about wintering over a Brugmansia.

Here is a link that might be useful: American Brugmansia and Datura Society