Sunn Hemp Cover Crop Height

Sunn hemp, a nitrogen-fixing legume from the tropics, can soar to an impressive 9 feet high in a matter of weeks.

Photo by Harvey Ussery

No gardening practice yields as many benefits as cover cropping, and growing cover crops in every season is as important as producing vegetables for your table. We too often think gardening reduces soil fertility, but in fact, the more you keep live plants growing, the richer your soil will become. Roots exude substances that feed beneficial soil organisms, including the amazing mycorrhizae (see Mycorrhizal Fungi: The Amazing Underground Secret to a Better Garden). Deep-rooted plants draw minerals from subsoil, which makes the minerals available to shallow-rooted crops. Dead plants, including invisible roots, decompose and release nutrients for use by subsequent crops. Plants also prevent soil erosion, and decomposing roots open channels for oxygen and rain, and provide pathways through which earthworms…