| This study was designed to evaluate the impact of several
planting depths and mulch depth, particle size and placement on tree establishment.
Except for one period 2 weeks after transplanting, mulch depth and mulch
particle size did not affect first-year stress (stem xylem potential) or
growth of 76 mm (3 in) caliper B&B transplanted live oak (Quercus
virginiana Mill.). Negative effects of deep [15 mm (6 in)] mulch 2 weeks
after transplanting only occurred for the mixed particle sized material.
Mulch placed over the root ball intercepted water causing a drier root ball
and resulting in greater tree stress and reduced survival following light
applications of water then trees with no mulch over the root ball. This
did not occur following heavy applications of water. Keeping the ground
near trees free of vegetation chemically had the same effect on post-planting
stress and growth, as did mulching. Soil over the root ball resulting from
deep planting intercepted water resulting in more tree stress and greater
likelihood of tree death in the first four weeks after planting. However,
trees planted deeply were less stressed three months after planting. No
root ball settlement occurred in the first 6 months after planting container
grown trees. |