Mo Bowman

We use to side dress a bit on sweet potatoes.

Bill

Wood ash is an excellent source of potassium, one of the three main nutrients needed by plants. However, it is also quite alkaline. Don't use it if your soil is already alkaline or use it on acid-loving plants (e.g., camellia, azalea, gardenia, rose, blueberry).

It is somewhat alkaline (basic), but not much. I'd avoind plants like potatoes and blueberries who prefer acidic (low pH) soils. Besides the ash, if you have any small bits of charcoal, you'll want to be sure to get them in to the garden as well. Charcoal charged soil has been reported by universities to be more fertile. Google Terra Preta, e.g.

My wife scatters some of the ashes on the garden but puts most of them into the compost pile to mellow out for a couple of years.

Paul

Forest soils are usually acidic, due to the action of decomposing organic material and fungi. I would think that adding wood ashes to a compost pile, where you are trying to achie.localve the same results, would be counter indicated.

The base (alkalin) part of wood ash is cabonate (CO3)--. The decomposition of organic material and cation exchange (H+) by the roots of plants will counter the pH effects of wood ash, but in the meantime there is the possibility that the minerals that you want in the garden soil (Ca, Mg, K) will be leached out.

My advice would be to apply the wood ash over the winter, but cease adding it a couple of months before you plant.

You may want to apply coffee grounds to your garden during this same time. Last year I put fresh coffee grounds on a couple of squash, and they immediately headed south. Conversely, coffee grounds added to my potatoes and blueberries was followed by an marked improvement in growth.

Hope this helps.

My point being that coffee grounds (at least from dark roast coffee) seem to be acidic, and may be able to take the edge off any small rise in pH caused by the wood ash.