Is it advisable to paint pruning wounds when pruning trees?
Do not apply a pruning paint or wound dressing to pruning wounds. The application of a pruning paint or wound dressing does not prevent wood decay and may actually interfere with the tree’s natural wound responses. Oak trees are an exception to the no paint recommendation. To prevent the transmission of oak wilt, oak trees should not be pruned in spring and summer. If an oak tree needs to be pruned during the growing season, for example to correct storm damage, immediately (within 15 minutes) paint the pruning cuts with a latex house paint. Winter (December, January, and February) is the best time to prune oak trees in Iowa. There is no need to paint the pruning wounds when oaks are pruned in winter.