"David (Normandy)" wrote in message
...

"Mary Fisher" wrote in message
t...

"David (Normandy)" wrote in message
...

The story you read sounds as though it were found in a sensational red
top,
professional gardeners still recommend the use of leached soot and
leached ash.

Mary

I can't remember where I read it now. I guess it makes sense if it is
left out in the rain to allow the noxious salts to leach out before it
is used on the garden. The problem only exists with coal ash/soot and
not wood ash/soot of course. Coal can contain all manner of toxic
minerals including arsenic, mercury, cadmium etc

David.

But only in very small quantities. Supposing they were absorbed by
plants - it would be in even smaller quantities and we wouldn't eat all
the plant anyway ...

I always leave wood ash in the open and wouldn't use it until it's been
rained on, it contains very caustic salts which can burn flesh and plants
until they're converted to the hydrated version.

Mary



Do I detect a fellow chemist?

Yes.

Potassium oxide (K2O) produced in the burning, getting hydrated to become
potassium hydroxide (KOH) which upon exposure to carbon dioxide in the air
eventually becomes potassium carbonate (K2CO3).

But I didn't know you knew that :-)

Mary



David