Landscape gravel, a collection of decorative stone used in garden beds, driveways, and pathways, offers a low-maintenance, aesthetically pleasing surface. Over time, its appearance diminishes as it accumulates organic debris, fine soil, and biological growth. Cleaning the gravel restores its bright, original color and maintains the integrity of the landscape design. Unclean gravel traps fine sediment, which impedes water percolation, leading to drainage issues and creating a fertile substrate where weeds can easily take root. A thorough cleaning process ensures the gravel continues to look fresh while preserving its intended function.
Clearing Surface Debris
The initial phase of cleaning involves removing the large, loose organic matter that rests on the surface of the gravel bed. This debris, including fallen leaves, branches, and litter, quickly decomposes into a soil-like material that supports weed growth. Using a leaf blower is the most efficient method for clearing large areas, but it should be set to a low pressure to prevent displacing the stones.
For materials too heavy or wet for a blower, a landscape rake or a flexible spring-tine rake is effective. These rakes skim the surface, catching debris while allowing the heavier gravel to fall through the tines. In areas heavily contaminated with organic matter and fine dirt, sifting may be necessary. This involves scooping up the soiled gravel and shaking it over a mesh screen to separate the clean stone from the sediment.
Rinsing and Deep Cleaning Methods
Once the large debris is removed, focus on the fine dust, sediment, and surface buildup that dulls the stone’s appearance. A strong stream of water from a garden hose equipped with an adjustable nozzle is often sufficient for dislodging loose dirt and surface grime. Direct the spray in a sweeping motion, allowing the water to wash the fine particles away from the area.
For more deeply embedded dirt or light algae film, a pressure washer can be used. Use a low-pressure setting, typically between 1,200 and 1,500 PSI, and hold the nozzle at a distance to gently clean the stone without displacing it. Stubborn stains or mold and mildew can be treated with a mild detergent solution, such as diluted dish soap, or a mixture of one part white vinegar to three parts water. Apply these solutions, gently scrub with a stiff-bristle brush, and then thoroughly rinse with clean water to remove all residue.
Eliminating Weeds and Biological Growth
Established weeds, moss, and persistent algae require focused treatment because they root themselves in the fine sediment trapped between the stones. For individual weeds, manual removal is the most environmentally sound method, ensuring the entire root system is pulled out to prevent regrowth. Tools like a stirrup hoe can cut weeds just below the surface without disturbing the gravel significantly.
For widespread growth, chemical or thermal treatments can be employed. Pouring boiling water directly onto small, newly emerged weeds will immediately damage the plant’s cell structure, though this is less effective on deep-rooted plants. Non-selective herbicides containing glyphosate can be applied for a systemic kill that reaches the roots, but care must be taken to protect surrounding vegetation. Natural alternatives like horticultural vinegar, which is significantly more acidic than household vinegar, can also be sprayed on the weeds on a sunny day to desiccate the foliage.
Maintaining a Clean Gravel Bed
Maintenance focuses on preventative measures to reduce the frequency of intense cleaning sessions. The foundation of a low-maintenance gravel bed is a properly installed weed barrier, such as a permeable geotextile fabric, placed beneath the stone layer. This barrier prevents underlying soil from migrating up into the gravel and blocks weeds from growing up from the soil below.
Regularly checking the perimeter for soil runoff from adjacent garden areas or lawns is also important, as this introduces fine particles that encourage weed seeds to germinate. Establishing a routine of light cleanup, such as a quick weekly pass with a leaf blower or rake, prevents organic material from accumulating. Occasionally raking or turning the gravel over will redistribute the stones, bringing a fresher layer to the surface and preventing compaction.