A well-mulched garden bed conserves soil moisture, prevents weed invasions and has that polished and well-groomed look you want in your landscape. Unfortunately, natural mulching materials, such as bark nuggets, can end up all over your lawn instead of staying in the bed. Edging the interior of the bed properly helps keep the mulch in place while still allowing it to perform its job. The mulch can form the main edge in a dug bed, or you can keep the mulch in place by edging the bed in stones or vinyl strips.
Till and amend the soil prior to edging and mulching. Mix in compost, fertilizers and other necessary amendments with the top 6 inches of soil. Remove weeds, rocks and other debris from the site when you mix in the amendments.
Pull the soil back from the edges of the garden bed, tapering the edges of the bed toward surrounding soil level to form a gentle slope. The interior edge of the bed must sit about 2 inches beneath the surrounding ground level, but the center of the bed should remain at the same level as the surrounding areas.
Spread the mulch over the garden bed to a 2-inch depth. The mulch will sit level with the surrounding landscape around the edges, and above the surrounding landscape at the center of the bed because of the slope. The slope toward the edging prevents the mulch from spreading outside of the bed.
Replenish the mulch with fresh materials annually in spring to maintain the 2-inch depth. The old mulch decomposes slowly, which improves the soil but drops the height of the mulch layer over time.