It's been a rather warm and rainy Summer around here, and I'm seeing some Black Goo growing in my creek rock driveway. Doing some research, it appears to be something called "Nostoc Algae". It is black, shiny, and rather gooey, and looks nasty. Has anyone had this growth in their driveway, and know of some commercially available "herbicide" that might kill it off? There is info on the Internet that talks about a couple of chemicals that can kill it, but no Brand names. I may pick up some Roundup the next time I go to the store, and try that, but if anyone has had this issue, and found a way to kill it off, I would be Very Interested.
I noticed the same thing a few days ago. According to the description and the fact that I Googled it is most likely "Nostoc Algae" that you were talking about. I have no idea where he came from. Recently, employees from everlastgates.com we have installed a new automatic gate for our house. We made a live fence on this gate, and recently I noticed Nostoc Algae on my gate. Lime obviously does not help. My husband will be in town in a few days and he will buy something that will definitely help, since I sent him some photos and he said that he knows how to get rid of it. I'll send you the name when my husband returns.
