Influence of vertical mulching and irrigation on the water status and growth of urban red maple (Acer rubrum)

Mulching has long been recognized as a treatment to improve the health and vigor of cultivated plants. In recent years, vertical mulching has been much discussed although, to date, there has been little research. Vertical mulching involves the removal of soil and its replacement with an organic amendment. In urban forestry, vertical mulching might be used to ameliorate difficult cultural conditions (especially soil compaction). I tested vertical mulching (radial trenching) on red maple (Acer rubrum) and compared it against surface mulching and no mulch. The study trees represented two cultivars ('Franksred' and 'October Glory'), and were established and growing near a major urban highway. I tested both types of mulching in conjunction with drip irrigation. My research focused on water status, growth, and phonological parameters over two growing seasons. The installation of the vertical mulch trenches resulted in some root damage but did not cause any long-term stress. Vertical mulching did not much improve the water status or growth of the red maples when compared against the control (no mulch). The surface mulch treatments tended to outperform the rest in most parameters of this short-term investigation.