Mulching of ornamental trees: Effects on growth and physiology

Two organic mulching materials applied to newly planted Tilia x europaea and Aesculus x carnea trees were evaluated for effects on tree growth and physiology. Both mulches were efficient in maintaining a cleared area around newly planted trees, although pine bark was more durable than coarse compost from mixed green material. Trees mulched with compost generally had greater height, trunk diameter, and current-year shoot growth. Differences were more evident in the first year in Aesculus and in the second year in Tilia. Mulching with compost increased carbon assimilation of linden leaves in 2005 when compared with pine bark and chemical weeding. Both mulching materials increased transpiration of horsechestnut in 2005. Little effect on gas exchange was found in 2006 in both species. However, because mulched trees were larger with longer shoots, whole plant leaf gas exchange was probably greater. Mulching had very limited effects on chlorophyll fluorescence. Results of this project have shown that mulching materials applied around trees after planting can positively affect tree growth without significantly affecting tree physiology. ©2008 International Society of Arboriculture.