When to prune your trees Arbor Day Foundation—When to Prune preparing your trees arborday.org arborday.org arborday.org arborday.org arborday.org Arbor Day Foundation tree pruning do not prune When to Prune Trees Arbor Day Foundation—When to Prune When to Prune Trees arborday.org arborday.org arborday.org trees should also be pruned Tree trimming wait until after fall