by Dina Lehmann-Kim, Master Gardener
On Thursday, June 2, 2016, a productive collaboration took place at the Shade Garden – a work party between Master Gardeners and the TreeStewards of Arlington/Alexandria. Two of the Shade Garden coordinators, Karen Smith and Carolyn Vincent, were on hand to welcome the TreeStewards and coordinate the work effort. This event grew out of a chance encounter between the Shade Garden coordinators and Jo Allen, a TreeSteward who had been planting native trees nearby on a Shade Garden work party day. Both organizations are part of Virginia Cooperative Extension, and have common missions and complementary skills, so the collaboration was a natural fit. With the help of the TreeStewards, Master Gardener interns and volunteers, as well as Kirsten Buhls, the Agriculture and Natural Resources Extension Agent for Arlington/Alexandria, and Paula Kaufman, the Master Gardener Program Coordinator, a lot was accomplished.
The work party with the TreeStewards began with a lesson on tree pruning techniques. Because trees are actively growing during this time of year, pruning was limited to removing crossing branches, dead or broken branches, and cutting back suckers and water sprouts (these are branches that grow from an adventitious bud at the base of a tree). The TreeStewards, led by Hugh Robinson, demonstrated proper pruning techniques, primarily using the garden’s centrally-located native redbud (Cercis canadensis) tree. Hugh noted to the Master Gardeners that dieback on the underside of a redbud is normal because of the heavy shade created by the dense foliage from the branches above.
Generally, tree pruning should occur in late winter (the late dormant season) just before new spring growth begins. The short window between late winter and spring means that there will be less time for pruning wounds to be exposed to potential disease. It is also easier to prune deciduous trees in winter since the leaves won’t block the overall view of a tree’s form making it easier to make cuts to create the desired shape. Please see this guide from the Arbor Day Foundation for more information on annual pruning from a tree’s initial planting to maturity.
As part of their mission of caring for street, school and park trees, TreeStewards remove invasive vines that are damaging the health of trees. Invasive vines such as the commonly seen English ivy, can spread vegetatively along the ground and grow upwards along tree trunks. If left unattended, the vines can wrap themselves around tree limbs, eventually suffocating and killing their host. (See image above of wild grape-vine removal). When English ivy grows vertically, it produces berries that are eaten by birds with resulting seed dissemination. For more information about English Ivy and how to control it, please visit: Invasive, Exotic Plants of the Southeast: English Ivy.
By the end of the work party, the garden’s redbud was beautifully sculpted and many of the invasive vines were successfully removed.