Moss is a non-vascular plant that anchors itself to surfaces like pavers using small, thread-like structures called rhizoids. This primitive plant thrives in environments with consistent dampness, shade, and minimal airflow. Airborne spores settle in accumulated debris and moisture trapped within the joint sand, leading to green or black patches that create a slippery hazard. Removing this growth requires a multi-step approach that addresses the existing infestation and modifies the underlying environmental conditions.
Physical Removal Techniques
Physical removal instantly clears the majority of the moss biomass from the paver surface and joints. For light growth, a stiff-bristled broom or brush can effectively sweep away the moss when the pavers are dry and brittle. Removing material lodged deep within the joints requires a specialized tool, such as a wire brush or a joint-cleaning scraper. These tools help extract the growth without disturbing the underlying joint sand.
A pressure washer offers a faster method for clearing larger areas but requires caution to protect the hardscape. Use a fan-tip nozzle and maintain a low-to-medium pressure setting, ideally below 1,500 PSI. Excessive force can blast away the joint-stabilizing sand, which locks the pavers together. Once the moss is dislodged, all debris must be swept and discarded to prevent spores from resettling.
Household and Natural Treatment Solutions
Household products offer cost-effective alternatives to dedicated chemical treatments for killing moss. White distilled vinegar, which contains acetic acid, can be mixed with water in a one-to-one ratio. Spray this solution generously onto affected areas and allow a dwell time of 15 to 20 minutes before scrubbing and rinsing. Since vinegar is acidic, minimize overspray onto adjacent lawn or garden beds.
Baking soda, or sodium bicarbonate, provides an effective natural solution by altering the surface pH. Moss prefers a slightly acidic environment, so sprinkling dry baking soda over damp moss raises the alkalinity to lethal levels, causing the growth to dehydrate and die. For spot treatments, mix the powder with water to create a thick paste. After sitting overnight, scrub away the dead moss and residual powder, then rinse completely with a hose.
Adding liquid dish soap to water creates a surfactant solution that helps penetrate the moss’s waxy cuticle and enhances other treatments. Boiling water poured directly onto the moss provides a rapid, chemical-free kill by scalding the cellular structure. However, it only works on contact and offers no residual or preventative benefit. Apply these natural treatments on a dry, sunny day to maximize contact time before dilution by rain.
Specialized Commercial Moss Killers
Specialized commercial products offer effective chemical solutions for widespread or deeply entrenched moss infestations. Many dedicated moss killers utilize metallic salts like ferrous sulfate or zinc sulfate, which are toxic to moss. These compounds typically turn the moss black within hours or days, indicating the cellular structure is destroyed. A drawback of iron-based products is their tendency to leave rust-like stains on porous paver surfaces, requiring careful application and immediate cleanup of any overspray.
Newer, non-staining commercial formulations often rely on potassium salts of fatty acids or ammonium nonanoate, which act as fast-acting herbicides. These chemicals disrupt the moss’s cell membranes upon contact, leading to rapid dehydration and death. Follow the manufacturer’s specific dilution and application instructions, ensuring complete foliar coverage, as mosses absorb treatments directly through their surface tissues. Safety precautions include wearing appropriate personal protective equipment and protecting nearby desirable plants from chemical drift.
Long-Term Prevention Strategies
Preventing moss centers on controlling the two primary factors supporting its growth: moisture retention and lack of sunlight. Trimming back overhanging tree branches and dense shrubbery increases the amount of direct sunlight reaching the paver surface, which accelerates drying after rain or morning dew. Improving air circulation around the hardscape further reduces the humidity levels that moss needs to thrive. Where water tends to pool, adjusting the surrounding grading or installing a simple drainage system can eliminate stagnant moisture.
Structurally protecting the paver joints is an effective preventative measure after the moss has been removed and the surface is clean and dry. Once the joint sand is stabilized, applying a high-quality paver sealant creates a protective, water-repellent barrier over the surface and into the joints. This seal inhibits the absorption of moisture into the paver material and prevents airborne moss spores and organic debris from settling. Reapplication of the sealant every few years maintains the barrier and ensures long-term resistance against re-infestation.