We have an aversion to chemical herbicides – both run-off and run-on (Anya feet), so have been trying to find a good way to keep the weeds out of our stone/brick patio and walkways. Crawling around and pulling weeds is rather effective. Anya beams with pride each time she gets a root too. But it isn’t a sustainable weed-control method for the entire space. The string trimmer can be used to quickly cut existing growth, but since the roots remain … they return right quickly. I imagine the root system can only sustain regrowth for so long, but we’ve never managed to chop them enough to prevent regrowth.
We had to clean our water softener’s brine tank – and I figure there had to be some basis in reality for the stories about Scipio Aemilianus salting Carthage after the Third Punic War. Not reality of the “he really did it” sense, but it isn’t like folklore has conquerors spreading well composted manure over the fields to render the soil useless. We pored the brine over our stone patio (I’m sure salt isn’t good for stone … but it had to go somewhere). There is one particular low-growing brownish-red weed that still grows, but it blends in well enough with the stone that I don’t really notice it. Other than that, though, *no* weeds for the entire summer. Burned the lawn some, and this is only useful if you find yourself with thirty gallons of brine that need to be dumped somewhere.
Next year, I have more techniques that I want to test: vinegar, baking soda, and boiling water. Hopefully we’ll find a few more approaches. Then next Spring, we’ll do a controlled experiment. 1/n of the patio and 1/n of the front walkway will be weed-controlled with each method. We’ll see which one kills the weeds without running off into the surrounding lawn and which prevents new growth for the longest time.