Hi all, I have this in my gravel! I used a BHS path cleaning product twice last year and again in june this year (August now) and I'm very confident that the problem has come from that. I have been recomended white vinegar by some local chaps, also diluted chloride (bleach). The stuff sold for keeping swimming pool water clean! That'll be my next move. Will let you know how it goes.
If you read this whole thread, the only reported success is baking soda which is also the least noxious and damaging chemical mentioned, so why not try that first?
Hi all, just to let you know this problem isn't only in England we have the algae on our driveway here in NZ. Comes up after spraying weeds with glyphosphate (Round Up).
Hoping the bicarb. of soda treatment will deal to it as it's awful stuff.
I tried bicarb with no joy...I just had to manually remove it all and it's not returned so far, we are in autumn now though.
Nostoc is a member of the Cyanophyta (actually they probably have some trendy modern name now*) which used to be called blue-green algae because some of them were blue-green and some of them looked like algae. However, they'e a much simpler (prokaryotic) form of life, much more akin to bacteria.
Why am I telling you all this? Because, not being an alga, it's possible that stuff designed to kill algae won't kill Nostoc. Looks like sodium bicarbonate's the stuff, but it might be worth doing some dosage investigation.
*Just looked it up. Cyanobacteria.
yep north auckland newzealand . I have the same problem . I also have used roundup on the drive. I see it along the gravel road also . I think the council may use roundup ont he edge of the road.
Also from Nth Auckland, New Zealand. I believe that alkaline soil also plays a part. We do not have any problems in our lawn or garden. The soil is quite acidic here, with clay and a thin layer of top soil. However, the gravel drive where the problem of Nostoc Commune is quite severe, has a lime base. We also use glyphosate to control the weeds.
So . soda bicarb may controll it ? Yep may drive has a lime base also.
Mid Devon, UK: gravel driveway. Same green algae, Nostoc. Its been on and off for 3 years now; disappears in dry summers and recently came back after spraying the driveway with Roundup (to kill the weeds) and we had lots of rain... will try baking soda....
I havnt had a chance to try the baking soda yet.Baking soda cheep if you buy from pool chemical supplyers.