What I know about the use of wood ashes as fertiliser or soil conditioner is that;
1). our ancestors (I think bronze age) used it, and
2). we, as a country, imported wood ash from America before the introduction of oil based fertilisers
3). I have been using it for the last few years successfully and no problem, my soil is good and crumbly and most of my veggies are fine, and the ones that aren't I can not directly blame on the ashes.
"So what is the question?", you ask.
Reading other gardening forums and web sites, there are such terrible stories of ground becoming too alkali and unusable (for three years one person claimed!), only put on one kilo per 100 meters another advises, others claim it's fine, chuck on as much as you want , etc. etc. there are anecdotes supporting either side of the argument.
Is there any one who has the definitive answer, 'Are bonfire/wood ashes good for the allotment, and is there a limit to how much you should use?' An answer based on scientific knowledge and understanding, not heresay, rumour or gossip would be appreciated. Thanks
I mix mine in the compost bins, if I put any in the soil I would give it a good spread round, apart from that I don't know much else about it. ::)
Sorry..can't give you scientific answer but I use wood ash regularly for having woodburner in house. I've learned to use ash by seeing from young age how my granparents used the ash in their small holding. I don't use it by bucket at the time but little and often fashion and always mixed with something else like damp grit or compost to 'bind' it and stop it blowing away and to able to spread it exactly where I want it.
Part from potatoes and cane fruit I apply it almost any crops during their active growing time.
One way using ash, what I haven't practice but my granny did, was dusting fruit bushes with ash..apparently kept many pest away..particularly gooseberry sawfly. She applied on bushes while the berries were still small so any rain would still have change to wash the clean before picking and after picking season bushes were dusted more regularly.
I've made most wonderful 'compost' by layering fine fresh wood chip with grass clippings and copious amounts of wood ash and letting it to 'mature' for 2-3 years....resulting proper black gold.. ;) ;D
I think there is enough 'truth out there' for such a wonderful stuff as ash by human beings been using it for as longs as they been able to light the fires. But like with anything else..too much of the good thing is no good.
Oh, and to add...
In Finland where I'm originally from...particularly Eastern areas, it was dense woodland (parts still is) and you couldn't grow anything in the ground as it was. It had to be cleared first and pockets of the areas were cleared by burning fires and crops then grown that fertile land that was result. As the effect of the ash wore out after few years..those pockets were left to over grow again and new pockets created.
First crops after fires were brassicas and next few were potatoes and rye..with a little help from animal dungs.
There is particular type of turnip name for that type of growing on the cleared areas =kaskinauris.
HSL has one type in their collection for their members..smallish but very sweet and hardy and it is said that the ash allowed the flavour of the turnip to develop its best...and..those turnips were also cooked in hot ashes and the soft sweet pulp was spooned out eaten as it is or spread on rye bread.
Here is something I found on google..
Potassium (or Potash) is the K in NPK and is the last number in a fertilizer ratio... i.e. 3:3:10 High potash content etc.. It promotes flower and fruit production, is vital for maintaining growth and helping plants resist disease. Potassium is naturally found in wood ash which is where it its name potash is derived from.
I collect all my combustible waste and collect pallets to burn on the plot and use this as a feed for my flowers and fruit plants.
Here's a very well-written article that adds a bit of the scientific background http://extension.oregonstate.edu/gardening/wood-ash-can-be-useful-yard-if-used-caution (http://extension.oregonstate.edu/gardening/wood-ash-can-be-useful-yard-if-used-caution)
It bears out exactly the good advice given by Goodlife :)
Oh..very good article..and I'm pleased that I've done it 'right' all these years.. ;D
I know it is not wood ash, but before the new regulations came in farmers always burned the stubble after the harvest and ploughed the ash back in the ground. All those farmers can't be wrong.