There are many deciduous trees that should only be pruned when they are dormant. You will find some helpful information on pruning, followed by a list of trees that are on the dormancy pruning list.
Some deciduous trees produce excessive sap in late winter and early spring, just before and when new growth begins. If you prune these trees, known as bleeders, during that time, sap runs from the fresh wounds. This does not hurt the tree, nor does it injure the tree. Prune the following bleeders during dormancy.
If flowing sap bothers you and you don’t like pruning in late winter or early spring, make cuts after the leaves have unfurled, around July. Do not prune when the tree just starts leafing out, or from late summer to mid-fall, when new weak growth can occur and the presence of pests and diseases is high.
Deciduous Trees to Prune During Dormancy
Maple, Acer species
Horse chestnut, Aesculus hippocastanum
Birch, Betula species
Hornbeam, Carpinus species
Hickory/Pecan, Carya species
Yellowwood, Cladrastis kentukea
Beech, Fagus species
Walnut, Juglans species
Osage orange, Maclura pomifera
Mulberry, Morus species
Poplar, Populus (some species)
Oak, Quercus species, Salix species
Chinese scholar tree, Saphora japonica
Linden, Tilia species
Elm, Ulmus species