Weeds thrive in the narrow joints of driveway pavers because these spaces collect organic debris, like dirt and leaf litter, which acts as a nutrient-rich growing medium. This environment consistently retains moisture, creating an ideal seedbed. Even the smallest crack offers protection, allowing weed seeds to germinate and establish a robust root system. Addressing this nuisance requires a two-pronged approach: removing existing plants and structurally preventing future growth.
Manual and Specialized Tool Removal
Physical removal is the immediate and most environmentally conscious method for tackling paver weeds. The goal is to extract the entire root structure, as snapping the foliage off results in rapid regrowth. Pulling weeds after a heavy rain or thoroughly saturating the area makes the sand and debris around the roots looser and more pliable for easier extraction.
Specialized hand tools target the unique geometry of paver joints. A crack weeder, often featuring a sharp, L-shaped or hooked blade, is effective for scraping out shallow-rooted weeds and moss. For deeper roots, a sturdy utility knife or a dedicated crevice tool can be inserted deep into the joint to sever the taproot below the surface. After the bulk of the vegetation is pulled, a stiff wire brush can scrub the remaining debris and small seedlings from the vertical sides of the pavers.
Targeted Chemical and Natural Killers
For weeds difficult to access manually or for broad coverage, targeted treatments can kill the plant tissue.
Horticultural Vinegar
Horticultural vinegar, which contains approximately 20% acetic acid, is a powerful natural option. This acid rapidly desiccates the weed’s foliage by disrupting cell membranes upon contact, causing the plant to wither quickly. Exercise caution, as high-concentration vinegar is non-selective and can potentially etch certain types of natural stone pavers if applied too liberally.
Boiling Water
A simple heat-based method involves carefully pouring boiling water directly onto the weeds in the paver joints. The thermal shock denatures the proteins in the plant’s cells, effectively killing the above-ground growth and damaging the shallow root crown. This technique is non-toxic but requires careful handling to avoid severe burn hazards and is best used for small, localized infestations.
Commercial Herbicides
Commercial non-selective contact herbicides, such as those containing Glufosinate-ammonium or Pelargonic acid, offer rapid chemical control. Glufosinate-ammonium works by inhibiting an enzyme in the plant, leading to the accumulation of toxic ammonia and plant death within days. Pelargonic acid, a fatty acid, acts as a fast-acting burn-down agent by destroying the plant’s waxy cuticle. When using any chemical product, ensure precise spot application with a low-pressure sprayer to prevent overspray from damaging nearby lawn or ornamental plants.
Joint Stabilization for Long-Term Prevention
The most effective long-term strategy for weed control is to create a physical barrier that prevents seeds from germinating and roots from penetrating the joint space. This begins with thoroughly cleaning all existing sand, soil, and organic material from the paver joints to a depth of at least one inch. A power washer with a low-pressure tip or a leaf blower can clear out the debris after manual or chemical removal is complete.
Using Polymeric Sand
The primary solution for stabilization is polymeric sand, which is fine sand blended with polymer additives. Once the dry mixture is swept into the cleaned joints, misting it with water activates the polymers. This causes the material to bind and harden into a dense, water-resistant material. The hardened joint material effectively seals the space, removing the loose soil and moisture weeds require to take root.
Proper application involves sweeping the material across the pavers to fill the joints completely, followed by compacting it with a plate compactor or hand tamp to ensure density. After compaction, excess sand must be thoroughly blown or swept off the paver surface before the final light misting. Following the manufacturer’s instructions for curing time and water application is necessary to achieve the maximum hardness and stability to resist weed infiltration.
Applying a high-quality paver sealant after the polymeric sand has fully cured provides an additional layer of protection. The sealant stabilizes the surface, enhances the color of the pavers, and helps to lock the joint material in place, further discouraging the establishment of weeds.