I FOUND WHAT KILLS THE GREEN GLOBBY SLIMY STUFF IN MY DRIVEWAY.
I said I would reply when the rain showed me which of my treatments has killed the Nostoc (the green globby algae-like stuff that appears in gravel driveways after application of glyphosate to kill weeds). I could not use everything that might have worked because I had to find something not toxic over time to pets if they got it on their feet.
Only THREE treatments have worked, so I'm going to ignore the accounts of everything else I have tried. The three treatments are:
Fire, using a propane torch to burn the Nostoc when it is crispy and black and dried a few days after a rain. This gets rid of it right away.
Washing soda (sodium carbonate, obtainable in the laundry section of a grocery store)
Slightly diluted concentrated bleach (sodium hypochlorite, also obtainable in the laundry section)
When applying either of these chemical substances, wear pants and wear shirts with sleeves and wear socks, shoes, and gloves. Also wear a mask so as not to breathe any fumes or get chemical splashed on your face. Wear goggles so as not to get it in your eyes. Keep the treatment as far away from your face as possible.
At first I did not think the sodium carbonate had worked. I applied it as powder and as a solution (1.5 cups of powder dissolved in 1 gallon of water and applied with a sprayer like one would use for weed killer). I did not think it had worked because even though it killed any accompanying moss and turned the Nostoc (the green globby stuff) a sickly yellow, it appeared to return after the next rain. But after the third rain, the areas treated with sodium carbonate were finally clear.
I got the concentrated bleach (it has the word "concentrated" on the jug) and mixed it 3 parts of the concentrated bleach to 1 part tap water. I also used a sprayer similar to a pump weed sprayer. It turned the Nostoc a sickly yellow. The globby masses were gone by the next rain.
Each solution worked best when applied to freshly swollen Nostoc just after a rain. Also, picking up as much dried, crispy Nostoc as you can before a rain really helps the treatments to work. DO NOT rake it as this crumbles it and acts like spreading seeds.
Last edited: 06 September 2017 00:45:04