1.   Another cause is extreme changes in soil moisture, and you can minimize this by watering regularly and by adding a mulch of bark chips.

2.   Another cause is extreme changes in soil moisture, which can be minimized with regular watering and a mulch of bark chips.

3.   He loaded large plastic bags with bark chips and wood shavings destined to be sold as mulch or landscaping materials to suburban shoppers at garden stores around the nation.

4.   Mulch the area around tree roots with bark chips to help hold in moisture and cut down on competition from lawn.

5.   Therefore, porous mediums such as bark chips, tree fern fiber and stones generally are preferred over soil.