Adair-->>Fred, I have a question: did the leaves curl up and fall off already? Does it normally drop its leaves this early?
Good question. I checked some earlier pictures. I have one taken in August, of 2012, and the leaves are starting curl. I would say it drops it leaves earlier than many might because of my garage storage. It's about 40 degrees in there all winter, so it leafs out towards the end of March, long before any natural trees here leaf out. I have other pictures in mid-October, about 3 weeks from now, where the leaves are gone. To be fair,the leaves didn't drop. I defoliated the ume, which I do every year about this time. But the leaves were pretty well gone. Curled up and many were dry.
Also, this tree is a Contorta. You don't have to wire contortas because they go all wiggly naturally. Occasionally, my ume will throw a straight branch. Those, I remove.
I use a different method to encourage flowers than the one you describe.
First, I have my ume in the smallest pot possible. When you do this, two things happen. The first and most obvious is that the surface roots get huge. This is not my discovery. I got it from Peter Adams' book "The Art of Flowering Bonsai."
The second, and less obvious thing that happens is that eventually, growth slows until finally, as I mentioned above, it stops growing altogether. I think my tree grew almost not at all for 5 years before I had to go to a larger container. All the time flowering increased year by year. I didn't prune at all during this time. The ultra-small container was doing the work.
As for pruning, after the ume has its shape set, I prune for maintaining shape June 21st or thereabouts. I don't prune again until after the last flower is gone. Usually I prune and repot at the same time, which is usually around the end of February. I get 3 or so waves of flowers a year, beginning in December and going through February. One year I remember the tree bloomed almost to April. The Ume has bloomed as early as December 7, which I remember because of Pearl Harbor.
To define the shape, I let all shoots go and then cut them back to 3 or 5 buds. Using this method, the tree will define its own shape.
If you want pictures of the early stages of my Ume, please get a copy of International Bonsai, 2012/NO. 1. Beginning on p.26 is an article I wrote describing the early development of this tree.