The effects of wounding and deep mulching on tree growth and internal discoloration in Acer rubrum ‘Northwoods’

Abstract

In 2007 forty-eight Northwoods red maple (Acer rubrum ‘Northwoods’) were subjected to basal stem wounds and three different shredded wood mulch applications (15cm deep with no stem contact, 15cm deep with stem contact, 30cm deep with stem contact). Trees were grown in a typical landscape setting for three growing seasons (30 months) after which they were destructively harvested to determine what effects basal stem wounds and different mulch depths had on stem growth, new twig growth, number of twig nodes, wound occlusion, and internal discoloration. Wounding did not have a significant effect on stem growth, new twig growth, or number of twig nodes. Trees with 30cm of mulch with stem contact had significantly greater final stem area and twig nodes than all other treatments. Mulch treatment did not have a significant effect on wound occlusion, stem discoloration in cross-section, or length of columns of stem discoloration observed longitudinally in bi-sections. Significant increases in growth parameters with 30cm of mulch may be attributed to enhanced water retention in these treatments.