We bought a foreclosed house this past March in South Las Vegas and discovered happily that there is a Wonderful (we're pretty sure) pomegranate tree in the backyard. We have no idea how old it is or how neglected it was, but it is somewhere around 15 feet tall and very bushy.

It put out beautiful scarlet flowers and started to develop fruit, but by July/August all of the fruit fell off. It is in desperate need of pruning, which I am planning on doing this week. I was hoping to train it more like a tree and I've read here in the forums about how to do that, but I'm not sure how old it is and therefore don't know how aggressive to be in retraining it. Should I leave it alone and let it stay a bush? Might the need for pruning have to do with the fruit dropping? Or could it be a young tree still that isn't ready to produce mature fruit?

Any advice would be greatly appreciated!