Thanks for the replies, Roger and Jim. However, would those products work on tarmac surfaces? They seem to be more for moss in lawns? Are iron compounds and the other compounds mentioned etc harmful to anything else apart from moss? I may be looking for the impossible but in light of our disappearing insects thread, I would like to use as few chemical pollutants as possible. Some of the products mentioned on the RHS site warn that they may kill grass, so presumably, they're not really great for insects etc?
As for liking moss, I have absolutely no difficulty with moss in my lawn - my lawn is full of it. In fact, it makes the job of mowing a bit easier as it means less grass to cut! And it's green so, as far as I'm concerned, it's an honorary grass(though my wife doesn't see eye to eye with me on my general lawn maintenance regime). However, I would prefer to keep by tarmac area black, if possible.
Originally Posted by: Lionel Hutz