The appearance of grass and other plants forcing their way up through sidewalk seams is a common issue for property owners. These plants take root in tiny pockets of accumulated soil and organic matter found within the cracks of paved surfaces. Effectively tackling this problem requires a multi-pronged approach that moves beyond simply cutting the visible growth. This article explores various proven methods for removing grass from your sidewalk, including physical, thermal, and chemical solutions.
Manual and Tool-Based Removal
Physical removal is one of the most direct and chemical-free methods for eliminating grass from sidewalk cracks. Success depends on extracting the entire plant, especially the root crown, to prevent immediate regrowth. Specialised weeding tools, such as a crack scraper or a stiff utility knife, are designed with a narrow blade to fit deep into the crevices.
You should work the tool along the crack to cut the grass below the surface and pull out the root structure where the stem meets the root. A stiff wire brush or a narrow trenching spade can also be effective for scraping out smaller weeds and the debris that supports their growth. After dislodging the grass and soil, sweep or use a shop vacuum to clear all debris from the crack. Removing this organic material reduces the potential for new seeds to germinate in the future.
Thermal Destruction Techniques
Utilizing high heat is a fast, non-chemical way to destroy grass and weeds that are confined to paved areas like sidewalks. Heat works by causing the plant cells to rupture, a process known as thermal shock, which quickly leads to desiccation and death of the foliage. This method is particularly effective for weeds with shallow roots, which are common in sidewalk cracks.
One simple technique involves carefully pouring boiling water directly onto the grass, ensuring the water saturates the plant down to the base. Using a tea kettle can provide better precision, helping to avoid splashing yourself or harming nearby desirable plants. For larger areas, a flame weeder or torch, which generates intense heat, can be used to flash-heat the plants without burning them to ash. When using a flame weeder, you must exercise caution by keeping a water source or fire extinguisher nearby and never using the tool near dry materials or on windy days.
DIY Natural Solutions
Household items can be repurposed into effective, non-commercial solutions for grass control in sidewalk crevices. High-concentration white vinegar, specifically horticultural vinegar with an acetic acid concentration of 20% or higher, acts as a powerful contact killer. The acetic acid rapidly draws moisture out of the plant’s tissue, causing the leaves to burn and die back quickly.
Household vinegar, typically around 5% acetic acid, is less effective and may require multiple applications. A solution using salt can also be highly effective, as sodium chloride dehydrates the plant cells and can sterilize the soil in the crack. However, salt should be used sparingly and only in the cracks, as it can damage nearby lawn or garden plants and may contribute to the long-term deterioration of concrete.
Using Commercial Herbicides Safely
Commercial herbicides offer a powerful and convenient option, but their use requires understanding the type of product and following strict safety guidelines. Herbicides are generally classified as either contact or systemic. Contact herbicides destroy only the parts of the plant they directly touch and are best for small annual weeds, providing a quick knockdown.
Systemic herbicides are absorbed by the foliage and travel throughout the plant’s vascular system to the roots, providing a more complete kill for established grasses. Apply the product on a non-windy day to prevent drift onto other plants or surfaces. Always wear protective gear, such as gloves and eye protection, and ensure the specific product is safe for use on or near concrete before application.
Preventing Future Growth
The most effective strategy against recurring grass growth is to eliminate the environment that supports it. After successfully removing the grass and all organic debris from the crack, the next step is to seal the void. Filling the cracks removes the space where seeds can settle and germinate.
Polymeric sand is a common material for this purpose; it is a blend of fine sand and polymers that hardens when activated with water, forming a firm, cement-like seal. This hardened material blocks the entry of new seeds and resists erosion, offering a long-term solution. Alternatively, a suitable concrete crack sealant or caulk can be applied to create a waterproof barrier. While sealing does not guarantee permanent prevention, it significantly reduces the frequency of future removal efforts.