Charles Naper Staff asked 13 years ago
This revolting slimy algae is forming on gravel/stone surfaces ~ pathways, carparks, cobbles. We think it’s Nostoc. First (modest) appearance was in 2010; now it’s widespread, sometimes in carpets up to 1.5cm thick (and counting).. Thrives on rain, even in this cold weather. Very unsightly, dangerously slippery underfoot. Can you suggest a chemical for control / elimination? (Drainage not an option) . (These Photos is from web; not my own.