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ronkw

Adding charcoal and ashes to compost??

ronkw
12 years ago

Just two to three shovels full to a 3'x3'x3' pile of partially "cooked" compost.

I burned a couple of, mostly oak, brush piles the other day.

Included some 2" diameter branches, which became char when the rain put the fire out.

(The pile will compost until spring, as my winter cover crops are in place.)

Would this be a healthy addition??

TIA

Ron

Comments (17)

  • Kimmsr
    12 years ago

    Some people (me included) will tell you that adding those wood ashes to your compost is not a good idea and others will tell you that it is okay. Cornell and most other universities will tell you not to.
    Wood ash will provide some Phosphorus and Potash but its major contibution will be Calcium Carbonate, around 50 percent, which can disrupt the composting process even in small quantities.

  • jean001a
    12 years ago

    Right on!

    It's better to add the ashes to your soil *if* the soil pH indicates it's needed.

  • toxcrusadr
    12 years ago

    There is a lot of evidence that the char is very beneficial to soils. I'm thinking of sifting it out of my ashes and putting it into the garden or the compost.

  • strawchicago z5
    12 years ago

    Kimmsr from MI is always right!! I always get good info. from Kimmsr, and they are always correct, backed up by University Extension sources. Here's a simple pH test for your compost:

    Chop a 50 cents worth of red cabbage really small. Buy 90 cents gallon of distilled water. Boil 1 cup of finely chopped cabbage in 2 cups of distilled water for 10 minutes. Let it cool down slightly so you don't scald yourself. Strain and discard cabbage solids, but keep the purple water.

    In tiny containers, I use old plastic fruit cups, or plastic Mott's applesauce cups. These are the samples: Few drops of vinegar - 2 teaspoons of baking soda - 1 heaping tablespoon of your compost - 1 heaping tablespoon of MiracleGro potting soil - 1 heaping tablespoon of your native soil, if pH is already tested professionally - 1 tablespoon of peat moss
    Pour equal amount of purple cabbage juice to each containers. The color changes should be: bright pink for vinegar (pH 2 to 3), deep reddish pink for peat moss (pH of 4), light pink for MiracleGro potting soil (pH of 6 to 6.5). If any of these pink color happens to your compost sample, then it's OK to add wood ash if you want neutral compost.

    The baking soda is alkaline, pH of 9, and the color should be greenish-blue. My pH of 7.7 soil have a blue-purple color in red cabbage juice . If your soil or compost tested blue-purple, or even more alkaline greenish blue, you don't need wood ash or charcoal, it would drive the pH past 8.

  • strawchicago z5
    12 years ago

    Hi Val: Thank you, I like the site you presented, very good info. It really depends on one's soil pH. The map of Illinois shows highest pH in my region, 1 hour west of Chicago, then lessens in pH as it descends down to central Illinois, then less clay, and more acidic by the border of Missouri.

    The Chicago Botanical wrote in their 6-year survey of roses that their soil is loamy clay with composted leaves, pH of 7.4 - My soil has pH of 7.7, tested professionally by EarthCo. - therefore the bagged soils high in wood ash and pH like EarthGro, or Scott's Premium top soil (with peat moss) are NOT best for my acid-loving plants.

  • toxcrusadr
    12 years ago

    Strawberry, that's a very interesting and handy pH test that I have never heard of. As a chemist (as well as winemaker) I'm aware that juices like grape, elderberry, beet etc. will change color with pH, but I never thought of using it so effectively for an inexpensive pH test. Not as accurate as a pH meter, but it will get you in the ballpark.

    Biochar (the bits of charcoal left over in fireplace or burn pit ash) will not affect pH though, and it could be added regardless of whether you're adding the ash with it.

  • strawchicago z5
    12 years ago

    My Mom in Michigan always put woodash from her stove into the garden. Her soil is neutral clay, and she has the best looking 5-acres loaded with flowers. Toxrusadr, thank you for the info. about biochar - what do you think about this info. from Charles C. Mitchell, Jr., Extension Agronomist-Soil Fertility & James F. Adams, Assistant Professor:

    "If soil pH is above 7.0 anywhere in the Southeast, one needs to find out why. Of course, some soils from the Black Belt prairie region of central Alabama are naturally calcareous and alkaline. They are formed from the soft limestone known as Selma chalk. Some soils could be as much as 50% lime and have a pH value as high as 8.3. There's not much one can do about this. Just grow plants tolerant of calcareous soils - not azaleas, camellias, gardenias, and blueberries. Soils that have an artificially high pH, however, may also have a high salt content. Some waste products such as wood ashes (not agricultural lime) applied to the soil could be high in salts (salts of sodium, potassium, etc.). High salts probably caused the initial damaging effects to the plants. With time, rainfall will leach the salts out of the rooting zone. A high pH (up to about pH 8.0) would probably create severe micronutrient deficiencies (iron, zinc, and manganese) and result in a general yellowing and poor growth. High salts will kill plants. "

    Thank you in advance for your info.

    Here is a link that might be useful: Lowering soil pH

  • toxcrusadr
    12 years ago

    Interesting stuff there!

  • albert_135   39.17°N 119.76°W 4695ft.
    12 years ago

    In the high deserts West where one can see great expanses one can see where there have been wildfires. After just a few years the the vegetation is richer and greener right up to the fire break. Desert soils in the textbooks are alkaline. There is something about the burning, and it's remains, that improves the landscape.

    If I recall you can see this near West Yellowstone too, where the vegetation that burned was mostly trees.

  • yugoslava
    12 years ago

    I came to this forum to ask about wood ash. I cleaned my outdoor fireplace and collected ash and bits of burned out wood. I also have charcoal barbecue (green egg) and use ashes from there as well, which I put in an enclosed composter. I found open compost pile doesn't do well when ash is added. The enclosed one composted everything. I would like to add I also used urine whenever I could and it speeded up composting greatly. I also remember about 12 years ago when someone at my home dumped ashes on tree peony during summer and next spring peony was dead. You have to be careful with ashes.

  • strawchicago z5
    12 years ago

    Thank you yugoslava for your input - which explains why I planted my peony on 2 bags of EarthGro BAGGED top soil, the leaves' edges turned brown, then it died. The other peony planted in my native soil is green and healthy.

    I also planted a Japanese Maple Tree on 10 bags of Scott's premium top soil. Leaves turned brown at edges, the tree did not grow any new leaf in 7 months. Product spec. of Scott's premium top soil stated that it does not have any sewage sludge, but I bet that they put plenty of wood ash to make the stuff so pitch-black - enough that I look like I had just come out of the chimney after working with bagged soils. I have to alcohol my skin to get the black stain off.

  • strawchicago z5
    12 years ago

    I have just found out why my acid-loving plants like Japanese maple don't like EarthGro bagged topsoil, Moo cow manure, nor Scott's Premium top soil. I tested them and found that they turn more green, thus very alkaline in red-cabbage indicator than my native soil (pH of 7.7).

    Here's an excerpt from http://www.natureswayresources.com/DocsPdfs/boiler.pdf

    "To keep costs down and profits up some producers of mulch, compost, and other bagged soil amendments use various types of "fillers." These include sawdust, ground pallets, plywood and glueboard dust (may contain dangerous chemicals), spent mushroom substrate that is called compost for marketing (high salts), paper mill sludges, bottom and fly ash from boilers (turns material black), etc.

    Boiler Ash (bottom ash) from coal is the most commonly used toxic industrial waste in the Houston area. It is so alkaline it will chemically burn mulch black in a few days. It is applied to ground up wood to make it look black or composted. Boiler ash tends to be high in salts and extremely alkaline. The products produced tend to be alkaline with high salt, with very high carbon to nitrogen ratios."

    I called my 87 years old Mom, who put wood ashes in her 5 acres garden for 35+ years with good results. She said, "I keep the ash away from roots of plants." The NPK of wood ash is 0 nitrogen 1 phosphorus 5 potassium - very high in potassium. Most soil are deficient in potassium, so wood ash would enrich the soil, but applying it directly to plant roots is not a good idea.

    I put coffee grounds NPK of 2.08 0.3 0.3 around my 10 rose bushes - they bloom more, and leaves are turn dark green. Coffee ground is a buffer, good for alkaline soil. It'a safer bet directly on plants than wood ash. Below is a good link for nutrients content of various substance: different manures, leaves, chemicals, coffee grounds, and cottonseed meal.

    Here is a link that might be useful: Nutrient Composition of various fertilizers

  • gonebananas_gw
    12 years ago

    It is curious that natural organic matter (leaves, roots, debris) seems to decay away more rapidly on or in alkaline soils than acidic soils. This is just a generality with I'm sure many exceptions (carbonate material also tends to make the remnant organic matter blacker in color for some reason). You would think this would mean that composing would procede faster with the addition of alkaline material such as ash. The comments and refereces above tend to toward discouraging the use in compost. I wonder what the reality is and the controlling factor(s)?

    Also, there is a type of tropical soil (I forget the name) that is rich in fine charcoal and is supposedly a notably better soil for crops.

  • toxcrusadr
    12 years ago

    Bananas, I think the soil you are referring to is "terra preta". I have read a little bit about it here and my impression was that deep deposits of it are manmade, from the addition of char over many decades or even centuries.

    The earlier posts about bags of black topsoil and the use of boiler ash are very interesting. If that is fly ash from coal burning power plants, it is usually very high in metals such as lead and would not be good for the garden. I am not sure such a use would be allowed under federal regulations. I will have to look into that.

    There could be other reasons for a black soil that harms plants. Anaerobic conditions comes to mind, for example.

    There is no doubt that bagged products vary considerably in quality by brand, region and season. I've tested them myself and saw proof of that. I sometimes use them, but always MIXING with my own soil and compost. I haven't planted in nothing but bagged products. If I did I would buy several products and mix them to avoid those problems.

  • judyallen123
    10 years ago

    I planted a 35 gallon red oak in October. I didn't realize you needed to wrap the tree in the fall. I just wrapped the trunk (January). How can I know if injury has already occurred? Also, do I unwrap the tree this Spring?

  • toxcrusadr
    10 years ago

    Judy,

    I don't know very much about tree wraping, but I think your tree will be OK. I have planted many of them including a couple of large ones, and I rarely wrap trunks. It helps with sunburn if the tree is not facing the same way. In winter the sun is not so intense and the tree is dormant so I'm guessing it will be fine. If you used a proper tree wrap (or plastic spiral) I don't think you need to remove it. Leave it for the first year or so till the tree gets established.

    This question might get more/better answers in the Tree forum (I'm sure GardenWeb has one - or more!). Also, you'll want to 'post a new topic' instead of appending the question to the end of an existing thread, unless you find one that concerns the same topic. People will be more likely to see it that way.

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