Spreading Hardwood Ash As Tree Fertilizer
'Tis the season for fireplace burning in our house - and likely in yours. That means that you'll have to deal with the ash that gets left behind after the wood burns. We burn hardwoods exclusively (so far this year, we've burned Cherry and Birch) and that means we end up with hardwood ash. Turns out, it has value in the garden as a soil conditioner and fertilizer. According to the Oregon State University (Notice...I did include *the* for those other OSU lunatics) Extension office, hardwood ash can aid in making the soil an environment that supports plant and tree growth.
From the OSU Extension article:
Because wood ash is derived from plant material, it contains most of the 13 essential nutrients the soil supplies for plant growth, according to Dan Sullivan, OSU Extension soil scientist.
"When wood burns, nitrogen and sulfur are lost as gas," Sullivan said, "but calcium, potassium, magnesium and other trace elements remain. The carbonates and oxides in the ash are valuable liming agents that can raise pH and help neutralize acid soils."
The fertilizer value of wood ash depends on the type of wood. According to Sullivan, hardwoods produce about three times the ash and five times the nutrients per cord as softwoods.As I mentioned, we use hardwoods. That means we're getting calcium, potassium, magnesium and others put back into the yard - or in this case - the beds where our Frans Fontaine European Columnar Hornbeams are planted.
You can see in the photos at the top of this post and right below that I've scattered some of this ash into the beds around a couple of the trees.
Ash helps change the pH and acts a lot like lime does in the yard. I've put down a bunch of Lawn Lime treatments, so this could be useful in our yard. However, my thought here is that I've been working the bed where these Hornbeams are located this fall - by adding some organic material and this ash is the latest. You can see some of the LARGE Oak tree leaves in the bottom of the photo, but those have recently fallen and will get either mulched up or removed. However, at the top of the photo, you can see some more 'mulched-up' leaf material. The gap below our fence on that side has grown a bit, which to me means that some of the material has been taken away. I wanted to build that up a bit and this leaf mulch was my start. I'll rake the ash in this week and then tuck the bed in for a long Winter's nap. Come Spring, I'll clean up the edge of the bed and dress it with a mulch (though...because of Lizzie...probably NOT Cocoa Bean Hull mulch like I do in the front yard).