[LivvyW]

My mum has a query with her compost heap, there is a substantial amount of what looks like grey/white ash in her heap. When she mentioned it to me i thought it was that white fungus that sometimes appears,but there really is a lot of it and it does look like ash.

She doesn't have a fire so it isn't ash.

Any ideas what is causing it and is it likely to be harmful?

[JayG]

If it wasn't put there it must have grown there; compost heaps are actually chock full of fungi and bacteria, most of which are invisible; white moulds are obviously easier to spot and not at all unusual in my experience.

[arugula]

Perhaps it is too damp.

[bigben]

I often find that if I have set up a full "darlek" with a good mix of brown/green containing some damp grass and regular sprinkles of old compost to get it going. It gets hot very quick and when I come to give it a turn over it looks like stuff has white ash on it.

[LivvyW]

Would you avoid using the ashy bits or mix it all in and use it anyway?

[Trillium]

It would be the compost getting very hot (cooking) and leaving the white ash. Yes, use it, as it's still very good an contains nutrients, but do be sure to scratch it into the soil or it will simply blow away.

[Alastair-I]

You often get this with a thick layer of grass cuttings, once they start to heat up they can get so hot that the end result is very ash-like.