Topic: Soot in Compost?

[Doris_Pinks]

my chimney was swept today, and the question is, the big bag of soot removed from me flue, can it go on my compost? I know that the coal ashes can't be used in the garden, but have no idea about chimney soot! ???
(I hate to waste it if it is useful!)  Thanks  Dotty "clean chimney" P.  ;D

[Palustris]

The book says (not me) that Soot is used to darken and warm the soil before seed sowing. If mixed with lime (no proportions given )it makes a very good insecticide. If put in a sack and suspended in a water barrel it makes a very good stimulant for pot plants. Store it dry. But compost heap, me no know.  It contains very little nitrogen and I suppose since it is mostly carbon it will help in the same way as adding woody material to grass cuttings.

[Doris_Pinks]

Thank you Eric, I shall retrieve it from my dustbin!! Hope the holly leaf wasn't too painfull Saturday night!  ;D

[Palustris]

All right till it got hot then I had Prickly heat.  :D

[teresa]

Hi Doris
Mother in law use to put the soot in the old tin bath and add water but I cannot remember what she watered with it.
Ashes are good for keeping slugs away from plants or if you leave them in a heap for a year then dig in the garden. Now what they do I dont know just knew mum did it that way.
Teresa

[Hugh_Jones]

There is little point in adding soot to the compost heap, its main uses are as either a soil conditioner, as Eric has said, with some fertilizer value, as a stimulant for onions, or as a surface dressing to deter celery fly and slugs (the slug deterrent part only works as long as the soot stays dry).

The fertilizer value varies according to fuel, but the best samples are obtained from chimneys where only coal is burned with not too strong a flue draft, when a typical ammonia content of approx 7% is likely.

Before use on the garden soot must be stored for 5 - 6 months.

P.S.  Hooray - we`ve all been promoted and I`m no longer a Junior member.  Teresa, how old do you have to be to become a Senior member?

[Mrs Ava]

so...why can't you use coal ashes on your compost?  ;D ??? ;D

[Hugh_Jones]

You can if you want, but they will almost certainly do more harm than good.  The reason is that coal ashes have already had the useful plant food minerals vapourised out of them, and any remaining are in the form of compounds which do not readily break down for availability to plants.  However, there are likely to be sulphur residues remaining which will `lock up` the calcium in the compost heap in the form of calcium sulphate (which plants cannot use) making the compost (and the soil) more acid.

You will also run the risk of adding cinders to your soil, which, for root vegetables, are about as welcome as you would consider toast crumbs are in bed

Does this answer your question?

[teresa]

Hugh the answer to your question is 21 and a bit
heeeeeeeeeeee
Congratulation to you all on getting 3 stars
Teresa

[Doris_Pinks]

I am still just a young um with me 2 stars  :'(  
Thank you for your soot answers, will store it as Hugh has suggested, and use it as a soil conditioner next year, thanks Eric! (BTW you can get cream for that!) Thank you for all your replies, knew you would have suggetions for me! :)

[ciderself]

Very jealous - I would love some soot as its supposed to keep nasties away. Can you get it from a combination/wood burning stove.
Have burned a load of weed roots and old wood/brambles on fires dotted around the allotment. Theres not too much of it but I have been adding these ashes to the soil.
I add wood ash (from prunings ) to the compost at home and stick some under the roses. They seem to like it. I hope its ok for veggies too?

[Hugh_Jones]

Yes, Ciderself, you can.  I`m not sure what you burn apart from wood (if anything), but soot from just wood burning has a lot lower ammonia content than coal soot, but apart from that it can be used for all the purposes already mentioned.

A word of warning about your wood ash. It contains a small percentage of salt and if you have clay soil (and only if) the addition of too much of this can reduce the clay to a permanent stickiness which can only be remedied by very large quantities of compost/manure or by use of gypsum. So if you have clay soil put the wood ash onto the compost heap where bacterial action will convert the potash into potassium nitrate which will permeate and enrich the heap (this is basically how the saltpetre for the gunpowder which fired Drake`s cannons at the Armada was produced - bet you didn`t know that one).

[ciderself]

Wow You really know about those chemical reactions. Thanks for the tip Yes soil at home(flowers/roses/trees -mainly acid loving varieties-very shady at back hence no veggies) is acid (still thick clay at the far end where I havent yet put so much compost- could easily make bricks)
Havent ascertained what allotment soil is yet -wonderfully light/sandy and a pleasure to dig so will need much muck ( considering tons of horse manure when I can locate it)wondering whether too late to sow green manure for winter
Some of the other holders have great banks of asparagus beds - all grow cabages/root veggies - have noticed scab on the potatoes - reckon this should give me some clues?

[Hugh_Jones]

The potato scab suggests that maybe a previous lottie holder has been a little too profligate with his lime. Large quantities of garden compost is the answer - an average pH level of 5.5 to 6.0 depending on what you compost and no lime added. That will quickly reduce the pH level of the soil

[tim]

a couple of handfuls of good advice there, Hugh!

In passing, I thought clay tended to be alkaline? Ours seems to be. - Tim

[Hugh_Jones]

The trouble is, Tim, that people use the word "clay" to mean two entirely different substances:-

1. Clay - soils which contain 50% or more of stiff unctuous clay and with a little sand and are lacking in both lime and humus, and

2. Marly soils, which are the debris of limestone rock decomposed and reduced to a paste.  They contain from 5 to 20 per cent of carbonate of lime, and humus is found in them.  They are distinguished as Argillaceous, Loamy or Sandy Marls according to the predominance of Clay, Loam or Sand.

Whenever I hear the word "clay" I immediately think of the former, then make a proviso in case the reference is in fact to the latter.

Sorry to be so technical, tim, but it`s better than waffle.

[Palefire]

I thought clay was the sticky stuff that water logs and is acid due to the ions and other electrically chemically type things in it? I did do soils at uni, but I have slept 3,500 times since then, with little reason to practise what I learned!!

Love, Palefire

xxx

[Doris_Pinks]

Where we are the soil is as Palefire describes, and though everyone tells you it is full of nutrients, it is a rotter to work! It is definately acid, the whole area is covered with rhodedendrons, azaleas and pieris!
Dotty P.

[Hugh_Jones]

Full marks, Palefire.  You have accurately described the stiff unctuous stuff I described as comprising the 50% or more of clay soils, and, as you will doubtless also recall, the pH value is the inverse logarithm of the number of active Hydrogen ions in the soil, which accounts for the acidity and the lack of lime or vice versa.

So our JOINT further advice to Tim is to buy himself a pH meter at the earliest opportunity and find out whether he has really got clay or whether he has Argillaceous Marl.  It might even make a difference to his future crop returns.

[ciderself]

Pretty sure mine's clay then as I've just been trying to plant out some foxgloves before they freeze in their pots ( a bit late 'cos of digging allotment) and even though I keep applying loads of compost/muck/old potting compost/grit etc in fact anything I can get my hand on, the soil is still hard to work in less cultivated areas.
Going back to one of your earlier points Hugh -I seem to remember putting saltpetre into home made sausages a long time ago. I dont think I'd fancy doing that now.