I'm not sure where you are but in most parts of North America, it's quite early into the fall which is not a good time to prune birch. Birch is a very difficult tree to prune at the best of times since the bark is easily damaged and can become infected. If you really must prune, wait until the tree is fully dormant in the winter. It's safe to prune up until early spring when the tree begins producing a new flush of leaves. Try not to prune or damage the tree after buds break or you'll notice that it tends to "bleed" sap. Arzeena, Horticulturist - Terra Viva Organics Homehelpnet Associate contributor
