We had a bumper crop of leaves last Fall, courtesy of my brother in law. Nice! Organic matter! My husband dutifully hauled them, ran them over with the mower, and spread them on the garden, along with liberal applications of wood ash from the stove. It worked for us in Oregon, right?
Not so much. The Oregon leaves had grass clippings mixed in, providing nitrogen, plus, the soil there is denser and more acidic. (Plus Ralph had a 55-gallon fish tank then, and we regularly added the sludge to the compost bin. When I tested the soil before planting this Spring, I had a shock. pH, um, a little high, at 7.5. (Too much wood ash.) Phosphorus and potassium? Fabulous! Nitrogen? Zilch. Ouch. The decomposing leaves had sucked all the nitrogen out of the soil in the process of turning into nice garden dirt.
We remedied this with bagged cow manure, but still, it’s an expensive way to learn. The cheap way to fix this is a weak ammonia solution, but we decided to keep our organic cred.