Be sure the berm is well beyond the edge of the root ball so water will be directed to the right place. Do not pile soil around the base of the tree. If drainage is poor, a berm is not recommended as you would not want to direct any additional water to the hole. Mulching Mulching is essential to the successful growth of young trees. Mulch helps conserve and extend available water to the tree, reduces competition by suppressing weeds, moderates temperature extremes, and acts as a barrier or visible marker for damaging landscape maintenance equipment.
Organic mulches support microbial activity important for tree establishment and growth.
Too much mulch can be harmful. Only 2 to 3 inches of pine straw or bark will be sufficient to provide weed control and moisture retention for the tree. Coarser mulches such as pine bark nuggets and pine straw do not support the growth of weeds as much as the finer compost materials. Herbicides can be used for additional weed control. Advances have been made in this area and products are available that are safe for the plants and are non-toxic to our environment.