Shovel or rototill the edge of the section in your yard you're landscaping. Make the trench about 4 inches to 6 inches deep to accommodate the Trex landscape edging. Cut away any roots that you encounter with an axe.
Pack and even the edge of the trench with a shovel around the entire circumference. Set the Trex landscape edging against the smoothed trench wall and then push into the dirt wall.
Connect the ends of the Trex landscape edging together by interlocking them into the proprietary connectors. Place anchors through the Trex edging about every 4 feet. Pound the anchors into the ground with a rubber mallet.
Shovel dirt against the exposed side of the Trex landscape edging and pack it down. Wet the packed dirt with a garden hose to settle it firmly against the edging.