Weeds sprouting between patio and walkway pavers are a common landscaping nuisance, disrupting the clean lines and aesthetic of hardscapes. These plants exploit the smallest gaps where organic debris accumulates, providing a growth medium for seeds carried by wind or water. Addressing this issue requires a multi-pronged approach, moving from immediate physical removal to targeted chemical applications and long-term preventative maintenance. This article details practical methods to eliminate existing weeds and implement strategies to prevent their return.
Manual and Mechanical Removal
Hand tools like weeding knives or specialized paver scrapers are effective for physically extracting plants, especially those with deep taproots. These tools feature thin, hooked blades designed to fit directly into the narrow joint spaces between the paving stones. The technique involves cutting the root below the surface and scraping out the accumulated debris, which is the primary source of the weed’s sustenance.
A stiff-bristled wire brush can be used to scrub the joint material clean for surface growth and moss accumulation. This mechanical abrasion removes small sprouts and dislodges the organic matter that supports future germination. This method provides immediate results without altering the chemistry of the surrounding environment.
Applying intense heat is another mechanical method, often achieved using a flame weeder, which instantly wilts and destroys the plant cells. The tool should be passed quickly over the weed, applying just enough heat to rupture the cell walls without igniting the plant material. Caution must be exercised near dry materials, and the heat must not be held in one spot too long, as this could damage or discolor the paver surface.
Natural and DIY Liquid Solutions
One popular method involves horticultural-strength acetic acid, typically 20% concentration compared to the 5% found in kitchen vinegar. This higher concentration acts as a contact herbicide, quickly desiccating the plant tissue upon application. Mixing the vinegar with liquid dish soap helps the solution adhere to the waxy surfaces of the weeds, improving treatment efficacy.
For effectiveness, the solution should be liberally sprayed onto the weeds during a warm, sunny day, as heat accelerates the drying action of the acid. Weeds should begin to show signs of wilting and browning within a few hours of treatment. Repeat applications may be necessary for perennial weeds with established root systems that were not fully saturated.
Applying boiling water directly onto the weeds is a simple, non-chemical way to achieve immediate cellular destruction through thermal shock. The high temperature instantly scalds the above-ground foliage and can penetrate slightly into the joint material to affect the upper root structure. This method is best suited for small patches or young sprouts, as the water cools rapidly and may not reach deeper roots.
Common table salt (sodium chloride) can be dissolved in water and poured into the joints to create a hostile environment for plant growth. This method carries a significant risk of long-term soil contamination in adjacent garden beds and can potentially degrade concrete-based pavers over time. Due to its persistent nature, salt application should be used sparingly and only in areas far removed from desirable vegetation.
Targeted Commercial Herbicides
Commercial chemical solutions offer targeted control over unwanted growth in paver joints. These products fall into two categories: non-selective herbicides, which kill almost any plant they contact, and selective herbicides, which target specific weed types. Since all plant life is undesirable in paver joints, non-selective contact killers are typically the most effective choice for immediate removal.
Contact herbicides work quickly by destroying the parts of the plant they touch, causing rapid wilting and die-off. For a longer-lasting solution, residual or pre-emergent products can be applied after initial removal to inhibit the germination of new weed seeds. These chemicals create a barrier in the joint material that prevents seeds from successfully sprouting.
Safe application requires strict adherence to all instructions printed on the product label to maximize efficacy and minimize risk. Users should wear protective gear, such as gloves and eye protection, to prevent direct contact with the chemical agents. Monitor weather conditions to avoid spraying on windy days, which can cause chemical drift onto desirable plants or areas accessible to pets.
When using chemical agents, keep pets and children away from the treated area until the product has completely dried or the required re-entry interval has passed. Carefully measuring the concentration and avoiding over-application prevents potential run-off into storm drains or unintended staining of the paver surface. Ensure the product is specifically formulated for use on hardscape cracks and crevices.
Long-Term Prevention Strategies
Shifting focus from removal to prevention involves eliminating the bare soil and organic matter that serve as a growth medium for weed seeds. The most robust preventative measure is the proper installation and maintenance of polymeric sand in the paver joints. This specialized joint material contains polymers that bind together when activated by water, creating a firm, semi-rigid joint that resists erosion and inhibits weed root penetration.
For successful application, the joints must be completely filled with the dry polymeric sand and swept thoroughly across the surface for compaction. The sand is then lightly misted with water according to the manufacturer’s directions. This activation process locks the sand particles together, stabilizing the pavers and reducing the available space for weed seeds. Consistent maintenance requires refilling any joints where the material has washed out.
Applying a high-quality paver sealant after joint stabilization adds another layer of defense against weed establishment. Paver sealants penetrate the surface of the stones and the joint material, making the area less porous and more difficult for seeds to germinate. This protective layer helps repel water and organic debris, denying weeds the moisture and nutrients required to sprout.