Newly planted trees do benefit from mulching, especially during the first years of establishment. Besides preserving moisture and stabilizing soil temperature, mulching controls competing weed growth. Above all, mulching acts as a barrier to keep lawn mowers away from the tree trunk, a leading cause of damage to landscape trees. Mulch could be made of shredded bark, wood chips or other organic matter. It should be 2 to 4 inches deep in a 2 foot radius around the tree, but do not allow the mulch to touch the trunk as it can cause rotting of the bark tissue.
To conserve moisture and promote water and air penetration, the back filled soil surrounding newly-planted trees can be covered with mulch consisting of material such as bark, wood chips or pine needles (although the acidity associated with pine needles is not suited for many plants). Mulch depth should be between 3 to 4 inches. Do not, under any circumstances, cover the area surrounding the tree with plastic sheeting since air and water movement are prevented. Porous landscape fabric can be used since it freely allows water and air penetration.
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