Adding rocks to the landscape improves the yard's appearance with a natural material. The University of Colorado Extension website points out that almost half of a household's water use goes for watering grass and landscaping; mulching with rock conserves water. Spreading small rocks around trees serves as an inorganic mulch, inhibiting weeds, insulating roots and conserving moisture. Compared with organic matter such as compost, rocks last season after season and provide a decorative element to the home landscape. Landscaping with rocks also reduces yard maintenance and protects trees and roots from mowers.
Select the kinds of rocks for the landscape; consider color, texture and weight. For example, lava rock has the advantages of being light and porous, allowing air and moisture to reach the tree roots. Choose red to add color to the landscape or black for a cooler look.
Buy rocks as mulch, accent boulders and some decorative rocks to add a rock garden feature, if desired. Creating contrast improves the appearance of the yard. If the area with the trees is plain, select some colorful rocks. To highlight colorful plants, choose simple rocks in gray, black or tan, based on what goes well with the house and fence.
Measure from the tree trunk outward to 6 feet and place a stone or make a mark with your shoe. Repeat at four or more locations around the tree.
Measure the diameter of the circle from a mark on one side of the tree to a mark on the other. Cut the landscape fabric to this size. Fold the landscape fabric in half and cut half-way up the fold from the edge to the center. Cut a circle out of the center the size of the tree trunk.
Spread the landscape fabric around the tree.
Build a rock border to contain the mulch. Dig a trench 1 to 2 inches deep around the tree along the marks to seat the rocks. Make the trench the same width as the average width of the border rocks, for example, 6 inches.
Arrange the rocks side by side along the trench. Build the border out of matching rocks or alternate colors or create a pattern. For example, set a pattern of four red lava rocks then one black lava rock continuing around the tree to surround a ring of black lava rock mulch.
Pour landscape mulch rock into the circle around the tree. If you have a wheelbarrow, push it to the rock border and raise the handles to dump the load of mulch. Otherwise, dump it from a bag or bin.
Even out the rock mulch around the tree with a shovel or rake.