Other resources:
Pruning Young Trees – International Society of Arboriculture brochure series.
Training Young Trees – USDA Forest Service Northeast Center for Urban and Community Forestry Urban and Community Forestry Factsheets.
Pruning Mature Trees – International Society of Arboriculture brochure series.
Maintenance pruning – USDA Forest Service Northeast Center for Urban and Community Forestry Urban and Community Forestry Factsheets.
Why Topping Hurts Trees – International Society of Arboriculture brochure series.
