Return to the Soil Forum | Post a Follow-Up

Effects of ashes on soil?

Posted by nostalgicfarm 5 (My Page) on
Fri, Dec 26, 08 at 12:07

We have a corn stove that produces a byproduct of ashes from the corn and fuel pellets that then needs to be disposed of. We also on occasion have ashes from a fire pit that could be disposed of. My garden soil is clay, but my other soil is very good(just not where I need my garden to be:) ) I am very curious about whether it is a good idea to dump the corn stove ashes (in the winter) directly into the garden. If they are not good there, what about in the compost pile. Would they be good or harmful is put in our already good yard soil? Obviously, if they are good for the garden, they would go there, and not the yard, as it is already in very good shape. If they are not good directly in the garden during the winter months, my second choice, if they are good for it, would be directly in the compost pile. I do not want to put them in my clay garden to find out later that I just added four years to my amendment process, so I am throwing this question out there in hopes that someone has a good answer for me. Thank you in advance.

Follow-Up Postings:

RE: Effects of ashes on soil?

What's your soil pH? Ashes tend to be very high in pH (remember reading about how ashes can be used to make lye for soap?). If your soil is acidic, you can spread the ashes on the garden and lawn to raise the pH. I'd be reluctant to use them here where the soil tends to be alkaline, but somebody in Colorado, where conditions are similar, has reported here that he spreads ashes on his lawn with no problems.

Composting is supposed to ameliorate the alkalinity, but I would not add a lot at one time for fear of overwhelming the compost.

RE: Effects of ashes on soil?

Wood ash is of course very variable but a ball park N-P-K number is 0-1-3. Most western soils have adequate amounts of potassium. Wood ash as has been said, a liming effect. So unless you live east of the Mississippi or on the wet west coast, I would not add wood ash to my garden without a soil test.

Adding wood ash in the compost can be just as tricky. Nitrogen is the most volatile of the nutrients. As the pH increases, ammonium turns into ammonia gas and leaves the compost pile.

This doesn't give you many options, does it? You can take up pottery and use it as a glaze ingredient.

RE: Effects of ashes on soil?

I did not have my soil tested last year. I was more concerned by the fact that it was clay. I was also too late in the season and out of funds to add amendments;( I am planning to add compost and some good soil to my garden area for some raised beds(mixed with the underlying compost), and will have my soil tested then.

RE: Effects of ashes on soil?

Used in small doses, wood ashes can be used to suppress slugs in the garden. Since I live in acidic NC, I use wood ashes on the garden directly, but only in the winter when there's time for the rain to work it into the soil.

RE: Effects of ashes on soil?

Whether ashes from wood stoves, pellet stoves, etc. are good for the garden is something that is often debated vigorously, and most knowledgable people will tell you it depends on how much and what was the source. Ashes can have nutrient levels you may need and they will be quite alkaline which could change your soils pH enough to make the nutrients in the ashes unavailable to the plants.
Before adding ashes to your garden have a good, reliable soil test done to see what those ashes might do, might contribute. If you have a soil pH above 6.4 you might not want to add any ash since that could raise the soils pH above 7.0 and very few plants like a soil pH that high and most nutrients become less readily available above that level.

RE: Effects of ashes on soil?

Aside from the pH issue, the particle size of ashes is mostly very very small - clay size, in other words. It would not do any good for improving the particle size distribution of clay soil, that's for sure.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Soil Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here