Mouldy Gravel

[PaperBlinds]

How can we clean mouldy blackened gravel (originally a goldy,light brown colour). It's under a very messy tree (goat willow). I don't want to use anything too toxic, but it looks grim atm.

It won’t be mould (which grows on stuff it can feed on), it will be algae.

it might be easiest to lift up and replace. You could either bury it (it won’t do any harm) or take it to the tip, where you’ll probably have to pay to get rid of it

Do you have a steam mop? Sounds mad, but try steaming it (at very close range but don't actually scrape the mop head on it).

Oh dear. I don't have a steam mop and could remove, but i think if left in the sun it would improve. I just thought maybe vinegar or something might help.