We think of gardening as a never-ending learning process. Just when something makes sense, we learn something new — or remember some detail we’d forgotten — and suddenly, Doh!… we feel like Homer Simpson. Such is the case with using leaves in the garden. We used to have so many. We’d heap up our compost piles and spread them over our garden. One not-so-bright day in November we decided that if we turned them into the soil they wouldn’t blow around as much. And, come spring, they’d decompose faster into the soil, enriching it with mineral-rich humus. Win-win!
No, lose. Even though we knew that carbon-rich materials use up nitrogen as they break down, we didn’t put it together with our garden soil, which of course we wanted to be nitrogen-rich. By turning those leaves into the soil, we were guaranteeing that we’d be losing some nitrogen for next growing season. Same thing happens with other carbon-rich materials: wood chips, sawdust, pine needles; even shredded paper and cardboard if you’re using it. Turning them directly into the soil will deplete nitrogen. (more…)