Re: River birch has no branches on one side
If you want to speed things up, you can try this (it’s worked for us before): Along the ‘bare side’ of the stem, make several horizontal cuts with a pruner or sharp knife. Just enough to cut through the bark and into the cambium. If you can make these cuts at or near nodes, or early buds, on the stem, these cuts may promote sprouting along the stem. These sprouts can then be trained into branches.