The ash from wood fires has been used for eons to make soap, They could be a deterent for slugs when applied in quantites too small to change a soils pH much, they could aid in keeping ponds clear of algea, they can be mixed with concrete, also. Much depends on the quantity, but as a general rule of thumb they should not be added to compost since that very alkaline nature really upsets the bacterial activity even in small quantities. There will always be those that will state they added wood ash to their compost and did not see any problem, even though there was a problem.

Thanks .... I would NEVER add the ashes to my compost pile. But it just pains me to toss those ashes into my trash. [I put them in the dump trash, not the recycle part]

Hmmmm..... I wonder if I can make a "tea" of some ash to pour over cracks in my walkway pavers, which weeds love to sprout in. At the very least it will make the minute part of soil inhospitable to other new seeds that fly by.

I will try some in the cement mixture when I start constructing stepping stones.

But by & large, it looks like trashing the ashes is the only solution.

I heat with wood. I toss ash onto my gravel driveway. Well, onto the snow on top of my driveway right now. I also leave a pile of it in my chickens covered area, and they dust bathe in it. Supposedly, that is an old time remedy to rid them of mites.
I do plan to make lye sometime.

There will always be those that will state they added wood ash to their compost and did not see any problem, even though there was a problem.

I'm one of those people. I blasphemously add wood ash to the compost, as well as fling it all over the place here on my alkaline soils. All the bits of charcoal, and when we clean the chimney, all the dried and crunchy creasote/ash stuff. Ash from six cords of wood a year, although not all that goes into the compost, call it 12 gallons of ash for a 6' dia by 3' high pile that gets all the compostables in the winter. The rest we fling on the snow, or if it's too dry out, we have a pit by a big tree that we dump the ash in. Tree loves it.

My compost doesn't read this forum, so it doesn't know it has wood ash issues ruining its life. When it thaws out in the spring, I mix it up, it heats up just fine, I then throw it all over everywhere just like everything else.

Right now, my ash is going on the ice on the gravel driveway, too. Works pretty good.

Can someone tell me what the difference is between wood ashes, widely believed to be bad for the soil, and charcoal, which is believed to be the secret behind the fertility of Amazon black soil? they're produced under different temperatures and oxygen contents I know, but how does that make the end products so different?

FWIW I live in an area of very acidic soils so I have never been intimidated by the alkalinity of wood ashes. I do add small amounts to my compost, and I've added it to the chicken house bedding, and I've sprinkled it directly on the soil as a dusting. I also dump excess wood and charcoal ashes in a pile in the woods, hoping for morels. No luck there so far.

This from WA State University Extension:
"Wood Ashes
Wood ashes are a readily available source of
potassium, calcium, and magnesium. Like lime,
they also raise soil pH. High rates of wood ashes
may cause short-term salt injury, so apply less
than 15 to 25 pounds per 1,000 square feet. We do
not recommend using wood ashes in alkaline soils."

I work in restoration ecology, and we burn prairies to restore native vegetation. It removes invasive plants and releases nitrogen into the soil. You get quite a flush of regrowth of native plants right after the burn, and we can go back to look at areas we planted, and plants planted in burned areas grow bigger and lusher than those planted in unburned, manually cleared areas. Still, these are acid soils.

I don't know if composting would change the pH of the ashes, but I don't know that it won't. Composting breaks down the long chains of molecules, so the pH could be altered in that process.

When my husband and I were married we moved into farm house his uncle lived in and let me tell you he put all his wood ashes west of house and when I was going to plant tulips I found out the ashes were 2-3 feet deep,I had to dig all that out. My tulips well they didn't do to well,but then the moles could have gotten to them, I planted a hundred and I believe around 10 survived. Now I have the low growing Spirea and Japaonia bush and they are doing fine. I been working the ground so that helped.

reg pnw,

As far as charcoal goes, pottery shards may have been responsible for some of the fertility of bio char. You can purchase ceramic powder now instead of breaking pottery.

We throw them on the dormant berry and asparagus beds, as well as on the wild blueberries, which like acid soil but seem to like wood ashes.

I've read about throwing and flinging wood ashes on the ice and snow but don't you track ashes into the house then? Or do you take your boots off in the porch?

We also now and then mix a handful of wood ash into the hens' sawdust bedding, which does seem to control mites.

Everything in moderation, even moderation. Adding wood ash in compost isn't bad it has to be in proportion to acidic ingredients.

Paul, at least for me, the ash on the ice melts through pretty quickly, which creates a chain reaction and we're left with two muddy strips where the car tires go. Which we get anyway when the ice melts naturally. So we always have to wipe the feet off in the snow once we get off the mud and onto something else.

finchlover, even I wouldn't try to plant anything in 3 foot deep ash.

Personally, I couldn't care less if other people throw wood ash on their gardens, lawns, flower beds, or in their compost. But as I've posted before on these forums, there are two 'schools' of ash people. Those who have never thrown ash, don't now throw ash, refuse to throw ash, and lecture everyone about how horrible it all is from a theoretical point of view.

The 2nd school are those who throw ash in their vegetable gardens, flower beds, out on the lawn, and in the compost. They look at the history of slash and burn agriculture on alkaline soils, see the burst of growth following forest fires that leave several inches of ash on alkaline soils, and generally have found that even after dozens of years of throwing ash out there, there is no harmful effect - quite the contrary. After a winter it is often the earliest to green up in the spring and grows the fastest.

On acidic soils, it makes even more of a difference. When we lived in South Central Africa, with leached, acidic soils in the highlands, it was one of the key tricks to growing a successful garden.

Try some in an out of the way spot and see if it works for you. Or not. Just be aware that there is an alternative school of practice out there. :-)

David52 mentions people who "... see the burst of growth following forest fires that leave several inches of ash on alkaline soils ... ". It has been my observation for over half a century that there is a burst of growth following wildfires. The OP from San Diego County shouldn't have to go far to observe this in a few weeks or a couple of months.

Albert -- I've had that thought, too .... but not sure how alkaline the native soil in the chaparral forest is. It is watered only with rain water, while our garden soil is watered with CO River water, which I think is alkaline AND treated with chlorine. .... And I don't know about the "burst of growth". Grasses -- most seeded by air to prevent erosion ... grow with the first rain. Followed by the flowers and shrubs whose seeds benefit from the burn. But the hills around Lake Hodges are slowly -- very slowly -- recovering from the fire 2 years ago.... probably as much due to the drought as to any other factor.

We had several acres of Chaparral burn in the October 2007 fire in northern San Diego County. Before the fire, the Chaparral was impenetrable; after, there was six inches or more of ash, skeletonized brush, and very little evidence of any charcoal. The ash melted into the soil after the first few rains.

The skeletonized brush has some hanging bark that is, possibly, charred to a millimeter in depth. The deeper layers of the bark and the branches are just dead wood most of which is still standing and has not separated from the crowns.

The basic difference between ash and biologically active carbon (as opposed biologically inactive carbon - coal or diamonds) is that ash does not hold water while the biologically active carbon does. As a general rule, biologically active carbon (humus) is said to hold four times its weight in water. Mulch and compost have somewhat less capacity to hold water in the transition to humus.

Charcoal has pore spaces that provide habitat for microorganisms and a carrying capacity for nutrients available to plants.

From what I have read, it isn't known, exactly, how the pre-Columbian Amazonian cultures produced Terra Preta do Indio, or that they did it purposefully, but there are indications that it may have been a concerted effort on their part. My favorite indication of that are the two photographs at Live Science dot com from the linked article. http://www.livescience.com/environment/060222_amazon_soil.html

The photographs do not seem to lend support to the author's text in the article. I have a tendency to think that our ancestors were more competent than some of us 'moderns' would like to believe.

Terran

Here is a link that might be useful: Black Magic Soil

Making charcoal for use in soils is, like making ethanol, an energy user. It takes more energy to make the stuff then you get from it.
Since wood ash is around 25 percent Calcium Carbonate (lime) and since it is very soluble putting sufficient quantities on soils can greatly alter the soils pH, which is why some of us caution people to not use wood ash on soils unless a good, reliable soil test indicates it will help no matter what other nutrients that wood ash may contain. Most all soil scientists will tell you the same thing.

If it's good enough for David and Tiffy -I'll give it another try this winter.

You've reminded me of other uses - scattering ashes on the wild rose hedge, in winter. We also fling urine on them when they're dormant - which adds up to the recipe below. A Finnish study found wood ashes and aged urine an excellent fertilizer. After ten years the hedge is twice as high and the blooms twice as abundant, and these roses are growing virtually in gravel.

We've also thrown ashes on snow on the lawn to sweeten the soil and improve growth - seems to get rid of weeds.

Here is a link that might be useful: wood ash + old p*ss

wood ash + old p*ss

What a great way to get my hubby involved with the garden this spring (his p*ss is very old)! He's always wanting to know what he can do to help. Now I can tell him "to p*ss off"! Excellent!!

Val

A google of "wood ash fertilizer" will indicate that the custom is reasonably wide spread, on several .edu websites, different application rates, but generally once a year, 5 to 10 lbs per 100 sq feet.

That pee+ash=big tomatoes is in several on-line journals, even National Geographic.

Ive been wanting to use my ashes...but i use duralogs in my fireplace. Would throwing ashes with duralog ash mized in be harmful to my plants?

Thanks guys!

I have a friend who uses cow or horse drippings, chic drippings and wood ashes. He mixes the cow/horse and the chicken drippings and adds water. Then he adds the wood ashes and uses a ph strip to test for a neutral reading. He continues to add wood ash until it is neutral. Then he makes trenches and puts this slurry into the trench and covers it with the dirt and plants the seeds. He says this works very well for a fertilizer.
I have a wood stove and I'm going to try this for my garden this summer.

Be careful when using wood ashes! I highly recommend reading the comments by the Cornell Extension Service on the following link. Its very informative:

Here is a link that might be useful: Cornell Extension Service

You can take a horse to water but you can not make it drink. Enough has been said.

Now, as we speak, the snow is off the ground, the springtime birds are chirping, its a pleasant 62º F (16.6º Canadian) out, and the grass is greening up. The fastest growing grass, the darkest green, is coming up through the inch (2.2 cm) deep ash blobs left from when I was heaving, like a drunken sailor on a pitching deck told to toss the slop bucket starboard, 3 gallon buckets of wood ash out across the snows of this past winter, now but a thought in the rear view mirror of the changing seasons.

I use wood ash to amend clay soil and I spread a little bit on my raised veggie beds in winter. The wood ash binds to the clay particles to break them up; I layer it with leaves and some pine needles.

I have acidic soil, but I read that although alkaline, it is not as alkaline as Lime; it also has many other nutrients than lime does. I also read that tomato plants love it (I can't remember where, but I read to put a whole scoop in the planting hole - sounds too much to me).

I use the charcoal by soaking it in jars of my very own natural urea for a week or so. I read that just adding plain charcoal is not good because it absorbs many nutrients in the soil, but if you soak it in fertilizer (that's what was recommended) it will slowly release nutrients instead.

You can use it on your lawn in place of lime, but I'm trying to get rid of my lawn, not make it grow faster.

I have used it on the driveway as an icemelt - it works but be careful of dragging it into the house.

And yes, you can make natural lye for soapmaking, but I haven't tried that yet.

"Now, as we speak, the snow is off the ground, the springtime birds are chirping, its a pleasant 62º F (16.6º Canadian) out, and the grass is greening up. The fastest growing grass, the darkest green, is coming up through the inch (2.2 cm) deep ash blobs left from when I was heaving, like a drunken sailor on a pitching deck told to toss the slop bucket starboard, 3 gallon buckets of wood ash out across the snows of this past winter, now but a thought in the rear view mirror of the changing seasons."

So the C stands for Canadian? I thought it stood for Celsius.

I forget. Are you one of the RMG regulars with native grass? If so, I'm not sure your results represent what would typically be expected. I used to have the first lawn to green up because I fertilized late in the fall. I haven't fertilized it several years and my lawn is once again the first to green up, but it's because the natives are taking over.

Celsius Campbell was a famous Hockey Forward for the Calgary Flames, back in the 20's. I'm pretty sure thats what my 5th grade science teacher said.

bpgreen, I throw wood ash all around the lawn for over 10 years, the previous owner did the same for 20 years, with no detrimental effect that I've been able to see. It greens up earlier, but that may be more a function of a bit higher temperature or retained moisture, I have no idea why. These spots lose their advantage pretty quickly.

When it's too dry in the winter to risk throwing ash with live cinders on the dry lawn, we dump it in a pit thats 4-5 feet from an oak tree. The tree seems to love it, the grass around the pit is lush, with who knows how much ash thrown over the years.

I have wheat grass out on the pond banks, the lawn started as a mix of KBG with other varieties, now the wheat grasses are making inroads. To be sure, I haven't thrown ash specifically on the native grass pond bank.

The older folk around, who grew up in the depression, save their ash to put on their vegetable gardens.

Once again, there are two schools of ash users. Those who will not and have not used ash, and those who do. :-)

I should also mention that in this alkaline soil environment, it is a real challenge to grow anything if the sub-soil has been disturbed for putting in a gas line, water line, or buried electrical. The only thing that helps there is steady amounts of organic matter, year after year.