Image: Wikimedia.
I have a built in, knee-jerk skepticism when it comes to the “notions and potions” school of gardening–the idea that some special substance will magically transform dead soil into a lush garden. That was my first reaction to biochar.
But it turns out that there’s something to biochar. This informative research summary from the University of Washington, Biochar: A Home Gardener’s Primer, changed my mind. According to U of W, biochar can:
- Improve soil texture
- Upcycle waste materials
- Increase microbial life
- Bind heavy metals (this is a big selling point for me with our lead and zinc contaminated soil)
U of W suggests purchasing biochar rather than trying to make it yourself. According to the authors its not easy to achieve proper pyrolysis at home. And they caution that biochar can cause problems for acid loving plants and worms.
I’m interviewing a biochar expert for our podcast today. Look for that episode in two weeks.
Have you used biochar? What do you think of the purchased versus home brew options?
I have heard biochars effectiveness is related to the soil type. Can you ask about this?
Great question! I will.
Yes, you shouldn’t use biochar in Southern California for example: http://patwelsh.com/wpmu/blog/soils/introduction-to-biochar/
Maybe this is obvious but what is the difference between biochar, charcoal and wood ash?
I’ve used it for the last three years and haven’t seen anything special – yet. I reclaim it from my wood burning stove. When the stove gets cleaned out I pour the ashes out on my long compacted-soil driveway, by the spring the snow has dissolved all the ashes and I rake up the char and dig into various spots in the garden. Maybe I should start monitoring those spots. My soil is too alkaline to have any ashes put into it. Other than pest control I don’t ashes do well in a garden unless you have extremely acid soil.
The U of W summary can be found at
http://cru.cahe.wsu.edu/CEPublications/FS147E/FS147E.pdf
The link in the article does not work correctly.
Thanks, Dr. O. Fixed!
Psst – that’s Washington State University (Wazoo) in eastern Washington with an excellent Ag school, not the University of Washington (U-Dub) in Seattle with an excellent med school.
The WSU extension offices are a really great resource for gardeners throughout the state. And if you ever find yourself on the main campus, you have to go to their creamery – great ice cream and the cheese is to die for.
Morfydd, Thanks for the correction. I just edited the post. They are a really great resource for home gardeners.