The best way to get rid of unwanted weeds from patio seams, cracks, and other hardscape areas (like walkways) is to use a liquid weed control like
Specially designed narrow-bladed weeding tools – sometimes called 'dandelion weeders' – for tackling such weeds are the most effective. More generally, a 'block paving knife' can be run along between pavers to sever most weeds. A wire-bristled 'block paving brush' is good at removing moss and the smaller weeds.
If weeds occasionally pop up, a spray weed killer can be used. Using an herbicide like RoundUp will not harm the pavers, and offers a quick solution to unsightly weeds on your patio or driveway.
Using Baking Soda
Baking soda is also helpful on how to stop weeds from growing between pavers. Just pour baking soda over your pavers and sweep it into the cracks. Do this ideally during spring or fall, and you should reapply every 1 to 1 ½ month.
Mix a bucket of soapy water (a couple of tablespoons of washing-up liquid will do). Simply apply the solution to the surface using a watering can or a pump sprayer and use a stiff broom to scrub the blocks clean, until all the dirt is loose - avoid using wire brushes to prevent damage.
The most effective homemade option is a mixture of white vinegar, salt, and liquid dish soap. Each of these ingredients has special properties that combine to kill weeds. Both the salt and the vinegar contain acetic acid, which serves to dry out and kill the plants.
Vinegar is acidic and will eventually kill most broadleaf weeds, but the acid will kill the leaves before reaching the root system, and the weeds may grow back quickly. For longer-lasting removal, mix 1 cup of table salt with 1 gallon of vinegar.
Whilst vinegar will not directly dissolve concrete itself, but it will degrade the cement that binds your concrete slabs or flags together. Extended exposure to vinegar will also cause any polish or sealant on your pavers to erode over time, leading to bleaching, stains and weathering.
When using a pressure washer, a turbo head that disperses the pressure of the water over a wider area which helps to reduce the wearing down of the interlock from the water pressure. The focus of the spraying should be on the joints to remove the weed growth and not the surfaces of the pavers.
Is Bleach a Better Weed Killer Than Roundup? While bleach has some weed-killing properties, it falls short when compared to Roundup, a widely used herbicide. Roundup, also known by its active ingredient glyphosate, is designed specifically for effective weed control.
Summary. Glycosulphate is the strongest weed killer chemical on sale and will kill grass too, but most gardeners won't need a product this strong as more targeted chemicals are nearly as effective.
Baking soda is an amazing household cleaner, and it can work really well on your pavers too.
When looking for a natural alternative to herbicides, a cocktail of vinegar, salt and liquid dish soap has all of the ingredients needed to quickly kill weeds.
The Dangers of Using Vinegar in Your Garden
Vinegar is a contact or "burndown" herbicide, killing what it touches within hours or days. The worst part is that it may looks like it's working, but weeds will then resprout from the roots, particularly perennial species.
What kind of vinegar do you use for weed killer? White vinegar with an acetic acid content of at least 5% will be required to kill most weeds effectively.
Glyphosate, the ingredient in Roundup and other products, is translocated from the leaves to the roots of a weed. Vinegar is not translocated. It is true that 5% vinegar (acetic acid) will kill young, tender weeds but it does little damage to established weeds.
The 20-percent concentration can do this in about 2 hours. Spot spraying of cornfields with 20 percent vinegar killed 80 to 100 percent of weeds without harming the corn, but the scientists stress the need for more research.
To clean paver slabs, you can use a detergent, such as Dawn, or a vinegar-water solution that is gentle enough to effectively clean without causing damage to your concrete pavers.
Use a specialist cleaner
Try a specialist cleaner like Wet & Forget, at Walmart, which you spray onto the surface of the paving and leave. It can also be used on steps, fountains, patio umbrellas and other smaller outdoor areas. It's bleach-free and non-acidic but will remove mold, moss and grime without any scrubbing.
Regular dishwashing detergent can make a suitable cleaning solution so long you're not dealing with any tough stains. This method is a good option to try if you have grease stains such as those from a BBQ. Hose down the area with water. Pour a little detergent as needed directly onto the pavers.
Similar to cleaning pavers with muriatic acid, avoid an intense concentration of bleach, as it can damage the pavers.