We suggest growing your combination tree as an ‘open center’ by trimming out secondary branches that grow into the middle. If one variety starts overgrowing the others, it can be slowed down by spreading the branch or tying it down. Summer pruning can also be helpful for the more aggressive varieties, while less vigorous ones can be stimulated by dormant pruning in spring. With a bit of trial and error pruning, you can keep all of the varieties well balanced.