[Chuffy]

Hi all
I have industrial quantities of leaves - two compost daleks full and a heap about 1.5m square. I also have a big bin bag full of soot from our chimney.

I know that leaves take a long time to rot down and that soot needs to weather before you spread it on the plot.

What I'd like to know is: can I just dump the soot on the leaves?

[Trillium]

I wouldn't. For the simple reason that ashes are very alkaline. And that the composting pH  balance of normally acidic leaves would be very altered to the point of  stopping if you add a bit too much of ashes.

The accepted measure is 1 cup of ashes to a 4'x4'x4' unit of compost or decomposing leaves. A bin bag full would be like drowning a worm in a lake.

Get a soil test done of your garden and see if you can add the ashes direct to the soil. If not, perhaps you have a mate who can use them.

[solway cropper]

The pH of your soot will depend on what you've been burning. If it's a coal fire there will be a fair amount of sulphur in it which will make it acidic. It was used in the old days as a feed for alliums.

Just dumping it on the leaves is not a good idea as the point of compost making is to have a variety of materials all mixed together. If you want leafmould then just make leafmould with nothing else. I'd be inclined to leave the soot and let it weather down for a year and then incorporate it into your soil or compost in small amounts. It can contain heavy metal residues and other toxins so you don't really want to be dumping large amounts of it anywhere.

[gowing238]

John has recently made an entry in his diary thing about soot. Heres the link
http://www.allotment-garden.org/garden-diary/1124/using-coal-ash-in-the-garden/

[mumofstig]

John is talking about ashes, I can't see any mention of soot.

[Chuffy]

Thanks all - I'll just leave the soot to weather and let the leaves do their own thing then!

[gowing238]

John is talking about ashes, I can't see any mention of soot.

Its all burnt innit!!! lol!!

[mumofstig]

Yes, they are both burn but the uses are different ....

Have alook here for more info

http://www.gardeninginfozone.com/ash-and-soot-%E2%80%93-as-plant-fertilizers

[JayG]

Although it varies in composition depending on the materials burned it consists mainly of carbon particles (neither good nor bad, although some say that being black it helps warm up light-coloured soils), various sulphur compounds including oxides which when dissolved in water make it rather acidic, and also creosote-like tarry compounds, many of which are known carcinogens. The last of these are far more likely to be found in soot from coal-burning fire chimneys.

It seems to me that the slug-repelling and disease-preventing properties are probably due to its acidic and toxic nature!

If well-weathered, especially outdoors and uncovered I would think that all you would be eventually left with is the carbon particles (but where did all the nasties go?)

It is not recommended for organic use, although I’m not sure it’s actually banned.