[mickeyboy]

Hi does anyone know whether or not coal and wood ash would be any good to add to my raised bed. I also have a pizza oven which uses only wood. My main crops will be chillis carrots, onions, spuds, salads.
Cheers

[Trillium]

Wood ash is okay to add to garden soil, but in limited quantities and preferably not fresh. Something about aging it first works a lot better for plants.

Forget the reason but I would never add coal ash to the garden.

[strangerachael]

But I saw on 'Victorian Farm' that coal ash - or soot (are they the same thing?)
- is good for roses. Cures blackspot or something.

[gillie]

Wood ash is high in potash, which is required by root vegetables, so I would give it to the potatoes, carrots and onions, and actually I would store it and sprinkle it on fresh during the growing season as potash washes out of the soil quickly.

I would not use coal ash as it will contain all kinds of nasty tarry substances.  

As for the Victorian Farm, I don't know -  but the Victorians used all kinds of obnoxious chemicals.  Organic they were not!

Cheers,

Gillie

[JayG]

I would agree with Gillie about wood ash, especially the point about keeping it dry before use.

I don't think there is as much benefit in using coal ash, but would like to point out that soot is a mixture of carbon particles and condensed organic coal distillates, most of which I would not even want to touch never mind put on my garden.

Yes, it will kill fungal spores like black spot, but that's because it's highly toxic to most living organisms!

[DavidT]

I would disagree with Gillie in as far as potash being good for rootcrops. potash is used for flowering and fruiting plants to aid production of fruit and flowers. Rootcrops need phosphates to improve growth. I would agree with using wood ash as a soil conditioner, though. The victorians tended to use coal ash for their paths. :happy:

[Trillium]

You'd need to take Victorian advice with a dose of salt. One of the things they firmly believed in was that too much sunlight was bad for you, hence the very small and very cluttered windows in houses they built. Yet they loved cycling. Go figure.

So, regarding gardening practices, think wisely before doing something as Victorians were sometimes not at all organic-minded, merely using up what they had without realizing the dangers, like lead-lined tea caddies.

[mickeyboy]

Wood ash is high in potash, which is required by root vegetables, so I would give it to the potatoes, carrots and onions, and actually I would store it and sprinkle it on fresh during the growing season as potash washes out of the soil quickly.

I would not use coal ash as it will contain all kinds of nasty tarry substances.  

As for the Victorian Farm, I don't know -  but the Victorians used all kinds of obnoxious chemicals.  Organic they were not!

Cheers,

Gillie

Thanks Gillie I take it i use it on the sane beds as the roots? Leave the chilli bed alone as well?

[bonfire]

I find it a strange idea that because some Victorians were cautious about exposure to the sun we should ignore their accumulated experience of what makes things grow better and what doesn't

There were generally more windows in Victorian houses than before and the main factors limiting the size of windows were about construction - brick and stone walls and wooden lintels before re-inforced concrete and steel frames allowed glass walls - and warmth - when houses were heated by open fires. These open fires became coal fires during the Victorian period and their experience of coal fires and the use of the waste products from them was therefore very soundly based.

Soot, most frequently on onion beds, and wood ash for potash were widely used on vegetables coal ash was not. I for one am inclined to follow their practice.

[gillie]

Sorry, senior moment, DavidT is correct.    Use wood ash on crops that are going to flower or fruit so put it on the chilis, and tomatoes if you are going to grow any.  I have spread it under my currant bushes in the past.

Cheers,

Gillie

[mickeyboy]

got it, thanks all.... 

[DavidT]

If you intend using soot, IT MUST be weathered for about 6 months. Do not use it fresh. I agree with bonfire, don`t be afraid to try old methods. Just use the coal ash for your garden paths, though.

[solway cropper]

I've made a nice path using coal ash and small stones dug from the plot. It's been waiting for its concrete cap for 18 months now and very few weeds have colonized it. For that reason alone I'd suggest it might not be good for growing things.

[JayG]

As a very long-time ago biochemist I just had to do some more research on this.

(Just trying to establish some facts so that folk can make up their own minds.)


Wood ash is a good source of various salts, especially potassium; overall these salts tend to be alkaline and are easily washed away.

Coal ash is low in useful salts, and may contain heavy metal and even arsenic residues depending on the source of the coal. Unlikely to do much harm in small quantities but then again not much good either.

Fresh soot is quite acidic due to the amount of sulphur compounds it contains; it is also likely to contain known carcinogens including dioxins. It is true that weathering it will remove most of these, but then its use as a slug deterrent, general fungicide and fertilizer will also have been almost entirely lost as you won't have much more than elemental carbon left. Not surprisingly, it is not recommended for organic use. 

[alfman]

 DavidT is on the button. Old time gardeners only used well weathered soot. They never used it fresh. ( I know 'cause I'm one of them.)