Weeds growing in the seams and cracks of a sidewalk, driveway, or patio can be annoying and unsightly and can be considerably more difficult to remove than weeds in a garden or flower bed. Ideally, you want to remove the entire weed including the roots, but this can be quite hard when weeds have squeezed into minute cracks in the paving surface. Fortunately, there are ways to rid yourself of this eyesore, including some environmentally friendly methods.
Your method of choice will depend on a number of factors. For example, you may be able to extract individual weeds by hand if you have just a few, but this method isn't practical for a sidewalk full of weeds. All of these non-chemical methods, however, are environmentally friendly if handled properly.
- Use a small flat-head screwdriver or a dandelion digger to dig and scrape the weeds out. Do what you can to get as much of the root system as you can.
- Boil water and carefully pour it on the weeds. Extreme heat will kill the entire weed, including the roots.
- Burn away your weeds with a small propane blowtorch, such as the type used for plumbing soldering repairs. There are also wand-style propane weed killers with long handles that allow you to torch weeds from a standing position. This method can also be used to spot-kill weeds, but take care not to ignite dry grasses.
- Make a simple spray with 1 quart of vinegar, 1/4 cup of salt and 2 tablespoons of dishwashing detergent. Stir it all together until the salt dissolves. Add it to a spray bottle and spray directly onto the weeds. This works best when there's no rain in the forecast for a couple of days.
- Of course, you can pull individual weeds. Pulling is especially effective for weeds with taproots, such as dandelions. This is best done when the soil is very moist; try watering heavily, then pulling steadily on the weed until it comes out entirely.
For weeds growing between brick or stone pavers, you can try filling the space with a material like a living ground cover, like thyme or sedum which will crowd out any weeds. Or, fill the spaces with shredded bark mulch or pea gravel. If the spaces between pavers are very small, look into a product called polymeric sand, which can be swept and watered into the cracks. Once dry, this sand forms a barrier that weeds can't grow through. Read product labels carefully, as there are some brands of this product that use synthetic binders, and others that use organic binders. Buy the organic one, if at all possible.
Glysophate Chemical Weed Killers
Any variety of chemical weed killers will kill weeds growing up through paving materials. Many people are concerned about the environmental impact of such chemicals, but if this is your preferred method, a product containing glyphosate is the best bet. Several commercial products use this chemical (Round-Up is one of the best known), and among chemical solutions, glyphosate is one of the least toxic, because it is immediately rendered neutral when it comes in contact with soil enzymes. Unlike other chemicals, it does not lurk in the soil and is not likely to poison animal life or be stored in plant tissues. Be aware, though, that this is a chemical that will kill all plant life it comes in contact with. This makes it well suited for treating weeds growing in paver surfaces since it's not likely to contact other plant life.
But also be aware that glyphosate is widely criticized by many proponents of organic methods who vehemently oppose any chemical use. And just because glyphosate is safer than some other chemicals does not mean it has no risks. Any chemical carries some health hazards, and some studies now say that glyphosate is likely a cancer risk when absorbed, inhaled, or ingested. So if you use any chemical product follow common-sense safety precautions:
- Reach for chemicals only when other manual and organic solutions are not practical.
- Mix it only according to label instructions. Never mix it in heavier concentrations.
- Avoid all skin contact. Avoid breathing any spray, and never spray on a windy day.
- Confine your spray to the weed only, and avoid spraying it on surrounding surfaces.
- Mix small quantities and use up all the product rather than flushing excess down the drain or dumping into the soil.
- Clean up sprayers by strictly following label instructions.