All cherries bear on long-lived spurs. Spurs on tree cherries begin to bear along two-year-old branches and can produce for 10 years and more. Count on the first crops in the third or fourth year after planting. Bush cherries may bear sooner.
As the sweet cherry grows, it should be pruned to the central-leader system described in Training Fruit Trees. Make sure that the leader or upper scaffold branches are not crowded and choked by lower scaffold branches that grow upward. After the tree begins to bear, prune out weak branches, those that develop at odd angles, and those that cross other branches. Be sure to head back the leader and upright side branches to no more than 12 to 15 feet so that the mature tree can be kept at about 20 feet.
Sour cherry trees differ from the sweet cherries in that they tend to spread wider and are considerably smaller. In fact, some varieties resemble large bushes. The sour cherry can be pruned in a central-leader shape, or — if you prefer to keep the tree smaller — prune it to a vase shape. It is quite easy to keep the sour cherry under 12 feet with either system.
Cherries need no thinning and little pruning after the first two seasons of growth. Sweet cherries may need heading back in the first years of growth to encourage branching.