Join Jen Kettell, Horticultural Technologist at the Arnold Arboretum, on Saturday, January 23 at 9:00 a.m. in the Hunnewell Building at the Arboretum for this single session pruning workshop. With no leaves on the branches to obscure your view, this is the best time of year to study a tree’s structure and shape it for improved air circulation, silhouette, and strength. Jen Kettell, an International Society of Arboriculture-certified arborist and accredited Organic Land Care professional, will explain the reasons for pruning and what to consider when pruning dormant trees, shrubs, and vines. She will demonstrate techniques, give guidelines for determining which plants benefit from winter pruning, and explain how plants heal from pruning wounds, even when dormant. Bring your questions to this classroom discussion and demonstration. Fee $30 Arnold Arboretum member, $35 nonmember.  To register, or for more information, log on to www.arboretum.harvard.edu.