Fertility Banks

A fertility bank is a cache of woody or herbaceous perennial plants that are grown specifically so their new growth (fertility) can be harvested and cycled back into the garden, orchard, or field. Plants are cut back yearly (or several times per year), and the trimmings are either composted or applied directly to the soil. In this way, the organic matter built up in the trimmings can be incorporated into the soil.

With woody plants, this process is called coppicing; with herbaceous perennials, it is called cut-and-come-again or chop-and-drop. Perennial plants that form the base of a fertility bank will regrow from the same root systems, so they do not need to be replanted year after year.

In one fertility bank my design partners and I planted, we used switchgrass, bush clover, creeping comfrey, and Russian comfrey. An autumn olive self-sowed there, and its high-nitrogen branches and leaves are coppiced. Compost bins nearby can be used to process the vegetation into compost, or it can be used as mulch directly in growing beds.

(From The Permaculture Promise by Jono Neiger)