wood ash- good or bad

hard wood ash- good or bad to add to the compost heap when i clean out the fire box. we have very acidic soils out here-
but is the ash to caustic- as it has not been washed and spent.
thanks folks
wayne

If you're trying to neutralize acidity, then wood ash will do the trick!

I'd recommend getting a pH meter or some test strips so you can find out what's happening as you go along. If you don't, it will be pretty hard to tell whether your plan helped out hurt until a year or two from now, when the composting is done and the plants have grown a whole season.

I disagree with adding a lot of wood ash to the compost heap. This will not be good for composting. Compost will almost always be more alkaline than your acidic soil, unless it is wood chip based compost, and does not need alkalizing by a bulk addition of wood ash. Wood ash is very caustic when water is added (this is how lye is made), and it will kill bacteria in your compost, and will do the same if added in concentrated amounts in your soil. I wouldn't add any to your compost at all.

It is better-Much Better-to add a dusting of wood ash on beds where plants that favor alkalinity, like beans, are going to be planted. Beans like a dusting near them for germinating. If wood ash is dusted out into your garden in a very fine way, then you are adding it as a trace mineral supplement in many tiny doses rather than as a bulk thing that would burn your plants and larger bacterial communities. The trace minerals and alkalizing of the wood ash can be a very positive amendment, but it must, like most concentrated fertilizers, be used in calculated moderation, if used at all. Compost, on the other hand, can be used pretty liberally, because it boosts the fertility through organic soil matter and microbial and fungal communities, in a much milder way. These organic substances and communities function in multifaceted symbiotic and synergistic ways to boost fertility.

I have a friend who adds a dusting of wood ash in his potting mix which has many ingredients, including peat which is acidic.

Certain crops, like potatoes, prefer an acid soil, or they will get scab on them. Scab exists in all soils but thrives in an alkaline soil.

Other crops and animals will promote alkalinity. If I'm not mistaken, legumes will help alkalize soil. Earthworms will alkalize any material that passes through them.

thanks fellas
will heed the advice!

The story on wood ash is a bit complicated. If one would read through the various research, university, USDA, and ag extension services reports about using wood ash, one would become more enlightened, but also probably more confused and hesitant. You see, not all wood ash is created equal. Plus the "powers that be" aren't all that sure about the stuff. "Leary" would be a good word.

Personally, I use wood ash on my homestead farm. I have for 12 years now. But before applying ash, I take a simple pH reading......or know from experience that a situation calls for it.....such as, putting a new area into growing vegetables. My soil is naturally quite acidic, so new land needs wood ash to bring the pH up quicker than coral sand alone could do. Because I am downwind of an active volcano and have acidic rainfall, the soil tends to acidify quickly. My applications of coral sand and burnt bone are often not sufficient to keep the pH where I want it. Thus my gardens often can use a light ash dusting between crops. Of course this is all dependent upon how active the volcano has been.

How much ash to apply? Truthfully, I don't know. I don't have each batch of my ash analyzed, so it's a guessing game. Rather than throw my soil way out of wack, I apply wood ash as a light dusting, then check pH a month later. I figure it's better for me to make multiple light dustings over time rather than over do it with too heavy an application.

The composition of wood ash is highly variable. It depends what species of tree, whether bark, twigs, and leaves were also burned. And where and how the tree was grown. So without a sophisticated test, I do not know how much calcium, phosphorous, potassium, and other minerals and metals are in the ash. But that doesn't stop me from using it. I simply choose to use it in moderation and watch what kind of results I get.

I used to use wood ash in my compost, but I no longer do that. Why? Because I noticed that the twigs in ashed compost didn't breakdown as compared to non-ashed compost. That comparison was based on compost that sat for six or more months. The same applies to my hugel pits. No ash during the construction phase. I would like the wood to breakdown a bit in order for it to take on sponge-like qualities and hold water. I'm no soil scientist, but I'm guessing that the ash causes the pH to be too high for good fungal activity. Lower pH favors fungi while higher pH favors bacteria. Wood decomposition is via fungal activity. If I didn't put wood into my compost, perhaps I would use ashes on compost. But I have found that the compost piles are a good means for processing my ongoing supply of twiggy material.

I've been thinking about how to use wood ash lately. I thought of putting it in bottom of chicken pen that has a thick layer of mulch in it and letting them incorporate it into compost.

Could be good, could be bad; the important thing to consider is what is the concentration? As Roberto mentions, a light dusting can be quite beneficial. And this is how Mother Nature applies things like rock dust and ash -- it blows in from somewhere else as a light dusting. If it is a heavy application -- like after a forest fire-- then you have to wait for the rains to leach it out and for the pH to return to normal.

Whenever you have a concentrated source of nutrients, like urine or manure or wood ash, you need to avoid direct application and think of a way to dilute the application. This may take the form of waiting until you hear the thunderstorm coming to go out and spread them. Nothing like a 2" gullywasher to take care of the concentration problem. Then again, you need balance; too much rain and all those nutrients are going to wash away.

If you look at the NPK values for wood ash and urine, you'll find that it is close to being a perfectly balanced all purpose fertilizer. Take equal parts and dilute them with 10 parts of water and you have an excellent solution for foliar feeding.

Traditionally, clean wood ashes have been used with chickens for their dust baths. Ashes were mixed with the soft dirt or sand of the hens chosen dust bathing areas. The idea was to kill the lice and mites that the hens picked up. I personally have no experience with this, but I've read about it in many old time journals and books. Apparently it doesn't harm the hens, but I'm not sure if the ash killed the skin parasites. So based upon this, using clean ash in your chicken pen should be ok. But your compost might be a bit alkaline when it's mature. You may wish to do a pH test on it before applying it to your gardens.

I keep saying "clean wood ash" because too many people burn other bits of trash and such, throw in excess BBQ briquettes into the woodstove, burn painted wood, or that sort of thing, thus contaminating the ash. The ash from BBQ briquettes and coal are not acceptable. So if I were using wood ash with my hens, I'd be careful to keep the ash clean.

John Elliott wrote:
If you look at the NPK values for wood ash and urine, you'll find that it is close to being a perfectly balanced all purpose fertilizer. Take equal parts and dilute them with 10 parts of water and you have an excellent solution for foliar feeding.

Very interesting... Wood ash and urine have been with man probably all along!

Roberto says, "Earthworms will alkalize any material that passes through them." I agree and think if your garden is healthy and you don't over do the application of ash then soil organisms in the garden will balance the ph out just right.

My 2 cents... I've used wood ash from oak for a long time, and learned some stuff the hard way. Added to a compost pile, it drives the pH way too high, around 8.5 to 9, and it seems to slow down the process. I never did an ash-to-compost ratio, I simply noticed my compost was not suitable for potting up after the pH test. My normal horse manure based compost comes out at 7.5 unless I add sulfur prills.

Now, I mix wood ash into my potting mix, which is 10% compost, 40% peat moss, and 50% bark fines. 1 tbs of ash per gallon, or about 4 oz. per cubic foot gives me a pH of 6.2-6.5 every time.

If I had acid soil, I'd spread it instead of composting it. The caustic in ash leaches very easily into the soil, vs. lime. You can even make soap from it, by extracting the KOH from the ash with rainwater!

John Elliott wrote:
If you look at the NPK values for wood ash and urine, you'll find that it is close to being a perfectly balanced all purpose fertilizer.  Take equal parts and dilute them with 10 parts of water and you have an excellent solution for foliar feeding.

A group of Finnish researchers were writing papers on urine vs urine+ash vs control comparisons on different crops. Urine+ash seems to work well.
https://pubs.acs.org/jafcau/article-abstract/57/16/7612/812923/Stored-Human-Urine-Supplemented-with-Wood-Ash-as?redirectedFrom=fulltext
https://www.researchgate.net/publication/40849524_Human_Urine_and_Wood_Ash_as_Plant_Nutrients_for_Red_Beet_Beta_vulgaris_Cultivation_Impacts_on_Yield_Quality

I plow it right into the garden along with the cleanup from chicken coop

I used to put my woodash in the compost, but like others above I found I had more than the pile would take - it turned grey and slimy rather than brown and crumbly. Now I save it for my vegetable garden. As I have acidic soil I can add plenty directly raked into the surface with only beneficial effect as far as I can tell. It looks like I've raised the pH from about 5.3 to 6.4 so far, so it's getting to a reasonable level now. I've just started a new garden though, so I still have plenty of use for wood ash there.

My soil trends neutral to basic/alkaline pH.   I don't add wood ash to my annual gardens -- too risky.

However, I do add some to my big raspberry patches. They don't seem to mind the pH shift and thrive on the nutrients.

I may add some to the wild saskatoon patches that have been producing well for us. They're tough and would probably appreciate the nutrients in our sandy soil.

I don't add it to the compost. My cold compost is slow enough already. It's tricky enough adding sifted char.

The dry ash I currently have is being stockpiled for ice melting on my steep driveway. We're expecting a freeze-thaw winter and I need all the help I can get.

I add a lot to the garden, but mostly buried. All winter we burn hardwoods and the ash goes in the garbage pit mixed with all the other kitchen waste. In the spring I cover it over with dirt and plant my garden. Been doing this for about 15 years and have not noticed any ill effects. I have seen that when I dig out the next year's pit, the layers of ash are heavily penetrated with roots. The plants seem to love the ash layers.

Thom Bri wrote:I have seen that when I dig out the next year's pit, the layers of ash are heavily penetrated with roots. The plants seem to love the ash layers.

Have you got acidic soil Thom? I notice roots clinging to bones or chalk if they are buried, and in my acidic soil it is obvious the plants seek them out.