Pumice Rock for Landscaping

Mulch

• As with gravel and other types of inorganic mulch, pumice rock insulates plants, conserves moisture and blocks weeds from growing through the surface. Although pumice can't supply minerals to the soil, its porous consistency provides a place for good bacteria to grow. Use large chunks of pumice so the rocks won't float away during a heavy rainfall.

Concrete Aggregate

• Pumice rock is often used for construction purposes. If you're pouring a concrete slab for a patio, walkway or driveway, or making your own steppingstones, use pumice to add a decorative touch to the surface. Once the slab is poured, seed the wet surface with small pieces of pumice rock and gently press them into the concrete with a wooden board. When the concrete dries, the surface will have a pebbled look. If you're molding artificial concrete boulders or large steppingstones, add small chunks or powdered pumice to the cement to make the finished product weigh less.

Rock Garden

• Rock gardens form an eye-catching, calming focal point in a landscape. Use different-sized pieces of pumice rock around boulders and stacked stones for textural contrast. Spread over the ground in a 4-inch-thick layer, pumice rocks allow water to permeate the surface and compact together under foot traffic. Use a mix of colors with hues of red and orange to add color to muted stones.

Borders

• Pumice rocks are a simple, casual alternative material for edging gardens and pathways. To block wayward weeds and grass from encroaching, lay a wide, 4-inch-thick border of large and medium-sized pumice rocks. Secure weed barrier fabric beneath the rocks to help block roots and support the rocks so they don't sink. While timbers, bricks and stone borders define shape, a low and wide pumice rock border creates a visual transition from a lush lawn to thriving plants and trees.