Removal—Identify wood that should be removed from older trees; and from younger trees:
Remove
•Old wood that has fruit buds that are very long (e.g. longer that 50 mm). These buds will produce cherries of lessor quality. They will not have as much calcium in the fruit compared with fruit from younger fruit buds, and that will result in cherries being softer.
•In vase, bush or open centred trees, consider removing the most vertical limb in the tree that will result in more light penetration and an inducement for the tree to produce more fruiting buds. Failure to remove it will result in more shading, fewer fruit buds, and lower quality cherries.
•Remove low hanging fine wood that will hang even lower with fruit on. Remove any that will be in the way of equipment or sprayed strips.
•Remove competing wood from the main limb once it reaches more than one third the size of the parent limb. If not removed, the next season it will be more than half the size of the parent limb and both will compete for reserves of nutrients to feed the fruit. It is better to produce two kilograms of premium cherries rather than four kilograms of average quality fruit.
Renewal
Removal of wood as mentioned above will allow renewal shoots to form either from existing shoots or buds, or the tree will usually make a new one. This is when a renewal of limbs and shoots is likely to take place.
When carried out annually, pruning at the end of winter–early spring invigorates the roots to push and assist in keeping the tree in good health, adding to a longer productive life for the trees.
Regeneration
Regeneration of younger trees, regardless of the management system, relies on simple rules for wood removal and renewal.
For instance in spindle style and Tatura trellis type styles, regeneration depends on the removal of competing wood so that the trees stay in balance.
Longer branches or limbs should be in the lower part of the tree and branches should get shorter as they near the top of the tree.
The same rules apply if it is one limb on a spindle type system, two limbs on a Tatura trellis type system, or multiple limbs with a KGB or vase type system.
Remember that pruning after harvest can be de-invigorating, but pruning in spring will be invigorating. Plan what must be done, then do it!
Additional information
Below is some information by Greg Lang, Michigan State University, on why renewal pruning is good for your cherry orchard.
Why renewal pruning is good for your cherry orchard
See this article in Tree Fruit August 2019
