Hardwood Ashes?

Ozark, MO(Zone 6a)

We removed a couple of big trees and did some trimming of others last fall - three oak trees and a hickory. The firewood has been cut and given to a friend, but I've got a lot of small limbs to burn. I'll have to push the piles of branches around with a tractor, and it'll make a real big bonfire.

My vegetable garden is 35' x 50', and it's clay soil amended with compost I've been adding for years. I've added small amounts of wood ashes to the soil before, but never this much. I'm thinking of building the bonfire in the garden, where the fire might kill a lot of weed and crabgrass seeds in the soil - then plowing and tilling the ashes in deep.

I remember the way lye soap was made with wood ashes in the old days, though, and I don't want to get the soil pH off too much on the alkaline side. What do you think?

Glenwood Springs, CO(Zone 5b)


I would not burn such a large intense fire over your garden. Beside sterilizing the soil, you may just create pottery. Organic material + clay + intense heat = bricks! :O

What is the pH of your soil now? Are you in that area of the country that has naturally acid soils?

You may want to burn that off site and spread a wheel barrow or two over your garden each year along with compost for the minerals the ash contains. I have read articles that say to approch the use of wood ash with caution.

Here is a link for an article on wood ash use as a soil amendment from Clemson University. http://hubcap.clemson.edu/~blpprt/bestwoodash.html

Living in the west, we don't need to make our soils more basic or alkaline. I added 50Lbs. of sulfur over a 1300 sq. foot area 18 months ago to help lower the 8.25 pH of my dirt. This Summer I will begin the laborious process of turning my clay like dirt into soil. At least I can use a mini track hoe for part of this project! :)


Ozark, MO(Zone 6a)

Pewjumper - Good point. I hadn't thought about how a big fire might fuse a clay/compost mixture into pottery. Let's not do that!

I get my garden soil tested every few years, and the first time I was about to make a garden in that spot it was 'way off. I had to add 150 lbs. of lime and several other amendments figured out by our University Extension. That got it squared away and I've been adding compost ever since, plus a smaller amount of lime every couple of years. The soil acidity is fine, 6.85 by the latest test, and I don't want to mess that up.

I'll take your advice and have the fire outside the garden, then I can add and plow in small doses of ashes for the soil. Thanks.

Glenwood Springs, CO(Zone 5b)


Since your pH is good for most plants, (I am jealous, LOL) and you have all those hardwood trees around. You may want to add a layer of leafs in the fall and put some Alabama Jumpers to work over the winter. These earthworms will pull a bunch of the leafs down into your soil over the Winter which means you won't have to do the work!


I have been working real hard at turning my clay/rock dirt into nice garden loam. It has been hard labor & a lotta cash. You however have the opportunity to hit the "easy button" and let the worms do the work. Let the worms do what they do best, make more worms & eat.


Ozark, MO(Zone 6a)

Pewjumper - Interesting. I've never heard the name "Alabama Jumper", but I've got 'em, or something very similar.

My garden is rich in compost, so I've got lots of regular earthworms of course. I've also got worms that startle me when I'm down working in the soil (A.J.'s?). They're about a foot long, they come shooting out of the ground, and they're strong and thrash around so you can hardly get ahold of one. For a split second when that happens, I always think it's a little snake and jump back - so I guess I'm the "jumper".

I've got a pretty good compost system. I've got three 10' three-sided bins made of oak pallets. I work and turn the compost with a tractor bucket, and add it to my garden the same way. My compost is made of chopped up oak and hickory leaves, green grass clippings, and green cornstalks and such. I don't purposely cover my garden with leaves over the winter but it works out that way anyhow, as we've got 60+ big oak and hickory trees on a six-acre place. Nature takes care of covering the ground with leaves in the fall, and it's all I can do to keep them cleared off the lawn.

Glenwood Springs, CO(Zone 5b)

That is almost a picture of heaven to a western gardener where most of us scramble for any organic material.

I have been absolutely amazed by the green landscape west of the Missouri River. It is something completely different from what I am used to being raised in rural Southern California and now Western Colorado.

Ten inch worms! Lord have mercy, I would jump a few feet in order to decide whether such a creature was safe to handle. We have no poisonous creatures here outside of mosquitos, (very few) & black widows.


Ozark, MO(Zone 6a)

Yes, I took an early retirement out of Southern California (San Bernardino County) 20 years ago, and moved our family back here to the Ozarks where I originally came from.

I always grew vegetable gardens in SoCal too, and it's a lot different here with all four distinct seasons and rain most every week. We sure like it.

I've been through Glenwood Springs, and know you're at about 6000 ft. elevation with a short growing season and what looks to be real poor soil. That'd be a tough place to grow a garden. If I lived there I might just take nature's bounty more in the form of deer, elk, and trout. I do that here too, but no elk and substitute bass and crappie for the trout.

Glenwood Springs, CO(Zone 5b)


I could & should shoot deer & bear from my deck with a compound bow, It would be really easy. But I do my ever expanding garden and folks turn me on to all kinds of elk, deer, beef & pork. All of the farm animals are raised very old school organic, hay, corn, etc, for feed.

Now I have reached the point where I can start giving a lot of high quality veggies back to friends. Pretty soon there will be an orchard, along with berries & all manner of produce for friends and those less fortunate.

God said..."tend the garden...." I love it.


Helena, MT

I don't know for sure if it was God who told me to tend a garden after moving to Montana, but it was a darn good idea. And the elk and trout are fantastic. Have to go back to Kansas for the deer though. Montana mulies are like eating boot leather. Middle boy actually does the deer hunting and has a hunting lodge there.

Sam, your thread got me to thinking about something and since my garden is much like yours, originally clay and rock (removed), but with copious amounts of composted manure added. I have however been giving thought to the wood ash idea as an additive like you, but Sonny changed my mind as to method. I spoke with a person at the mill down the road apiece and they offer wood chips for free if you shovel your own. When the wife gets back from Texas next week I had planned on getting several pickup loads. Each spring I do a burn off of the garden refuse at the back of the lot and I'm now considering burning a pile wood chips along with the refuse. I can then add the ash a little at a time where needed. I have also decided to line the bottoms of my raised beds with layer of these wood chips before adding composted cow manure and other materials which make up the growing media. Good article on wood ash Sonny. Will spend some time this morning after I catch my supper reading this one over.


Sacramento, CA(Zone 9a)


Have you thought about biochar as a possible use for your wood? Darius has written several articles on the subject here on DG and it's a pretty neat idea. Here's a link to the articles on the subject:


Everett, WA(Zone 8a)

Unless you specifically wnat the pH-raising effect of ashes, you'll get more organic matter out of wood chips, brush and even logs by burying them and growing on top. They will hold water through a long dry spell.

Apparently they have a name for that in Eastern Europe: Hugelkultur.



Kalispell, MT(Zone 4b)

Morgan living in a more acidic area than you I use wood ash to kill grass. I learned it a few years ago when I used a leaking wheel barrow to haul ash to my wood ash pile. Every where it dropped I killed grass. The salts of wood ash is rich in mineral but very alkaline! So I learned to add a little ash to my compost as I spred it around the soils when applicated. Of course the compost is very acidic so the sprinkling of ash does a great additive to the compost to feed N, Ca(which we don't need), Mg, K, MO, and other trace minerals to the compost. I have a yard of ash every year from wood burning in fire place and garden refuse burn. I have a place down hill that I dump ash in a large pile that kills everything within 6" around pile, except alkaline weeds. This runs off to the neighbors property as the rains and snow wash it away. I have not found any use but compost for the wood ash.

Helena, MT

Very interesting Dean. What is MO, molybdenum? I have access to western cedar wood chips which I could burn possibly to make my own wood ash. The idea of controlling invasive grass into my garden appeals. Isn't it interesting the things we can learn through awareness of little mistakes we make. I am always amazed at how much we can learn from gardening, itís a never ending process.

Kalispell, MT(Zone 4b)

Not Dean but Steve. Moly is MO. I'm sure you have a fire place somewhere to get ashes, if not come over to my house and get some we will have a long cup of coffee and discuss spring projects. Anytime you are here let me know.

Efland, NC(Zone 7a)

Oh m'gosh...

"have a place down hill that I dump ash in a large pile that kills everything within 6" around pile, except alkaline weeds. This runs off to the neighbors property as the rains and snow wash it away."

Sofer, I hope your neighbor still likes you! *grin

I save and use wood ash from my wood stove...store it in a metal trash can high and dry. I'd have to go look it up but if I remember correctly a full wheelbarrow load can be used per 100 sq ft but not on a consistent basis AND your local pH should be taken into consideration. I oftentimes use it to dust plants with, for bug control...it seems to deter flea beetles and other sucking insects.

Corey, I've been reading up on Hugelkulture, too. Pretty interesting, ain't it!? I'm sure I'll put it in action at some point due to the trees/brush and such I have here from time to time.

Shoe (in the midst of spring weather so exhausted from setting out umpteen hundred onions, leeks, and a few Calabrese plants. Cold brew time...)

Glenwood Springs, CO(Zone 5b)


I will reintroduce an excellent link on wood ash from Clemson University. http://hubcap.clemson.edu/~blpprt/bestwoodash.html


Kalispell, MT(Zone 4b)

The neighbors who receive the run off is about 200 acres of Elk grazing on the meadows.

Thumbnail by Soferdig
Efland, NC(Zone 7a)

Wow! Sofer, what a picture! Elk heaven.... And it certainly doesn't look like your ash runoff has done anything negative. What greenery. That's beautiful.

Pewjumper, thanks for the link. I'll go read up on it when I finish my greens and smoked turkey leg. (yummy!) Much obliged.


Bozeman, MT


I checked out your links on Hugelkultur. At the bottom of this one:


it says: "Other gardeners plant the bed with cover crops for the first year to improve the fertility even more before adding vegetables or other plants."

Does anyone know what is a "cover crop?"


Everett, WA(Zone 8a)

Cover Crops:

Alfalfa, Fall Rye, buckwheat, clover, vetch, oats, field peas, cow peas ... anything that grows fast.

All enrich the soil and prtect it while they are growing. The idea is to grow something fast in soil that would otherwise be bare and idle and eroding, then plow it under. That adds organic matter.

Some will fix nitrogen from the atmosphere, and add that to the soil.

While it's growing, it prevents erosion and may choke out weeds, if it grows fast and thick enough.

Fall Rye (and probably others) are nice because you can plant them in fall, or even late fall, and expect them to take root and live for a while in cold weather..

Another term that used to be used is "green manure".

Probably best if it is an annual (so it doesn't come back when you don't want it).

The roots are also vigorous and deep for most cover crops. I've heard the claim that some cover crops will "dig deep" for phosphate or potassium, pull it out of the subsoil, and "bring it to the surface". Even if that is optimisitc, the roots do break up soil and leave channels behind when they die.

Some even plant great big radishes like oilseeed radishes specifically for their ability to dig deep holes and fill them with composting organic matter! I heard the term "tillage radish". I'm not making this up! They have their own website: http://www.tillageradish.com/.

There are many lists of cover crops, ranking them by how much organic matter they produce, N-fixing ability, tolerance for dry soil or clay soil or low-nutrient soil, cold, heat, regional advantages etc.

After buying teeny-tiny flower seeds in packets for several dollars, and getting what seem like milligrams, it was a thrill to go to the Grange Co-op and buy POUNDS for less than $1 per pound.

And those big seeds (fall rye) were as vigorous as they were large. No "stratification" or coddling needed. I put some on a damp coffee filter, and they elbowed me aside as they raced out the door, hoed a little patch of soil, and planted themselves.

I guess now I am exaggerating, a little.


Bozeman, MT

Thanks, Corey.

So much to learn . . .


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