For a couple of years now, Managing Cover Crops Profitably has been my cover crop bible.  But although the publication has great depth, it only covers 19 species, and I'm starting to get a handle on which of those will work on our farm and which won't.  Being who I am, I'm not content to rest on my laurels and stick to buckwheat in the summer and oilseed radishes and oats in the winter --- I want to keep trying new things!

Enter the Northern Great Plains Research Laboratory's Cover Crop Chart.  This publication replaces depth with breadth, presenting the highlights of 46 cover crop species both pictorially and in the form of a bulleted list.  That's the source I headed toward when I started hearing about sunflowers used as a cover crop.

As I already know well, sunflowers are great for attracting pollinators (and for feeding chickens), but how do the plants operate as a cover crop?  The Cover Crop Chart mentions that sunflowers pull up nutrients from deep in the soil, perhaps because they're good at teaming up with arbuscular mycorrhizae.  Sunflowers' C:N ratio is listed as 11 to 14 for the leaves, 41 to 46 for the stems, 50 to 68 for the roots, and 14 to 19 for the flowers.  What that data says to me is that sunflowers are good to plant in troubled soil that's going to be taking the whole summer off, or in the chickens' winter yard, scratched bare from last year and needing some high carbon materials (and playthings) to keep your flock happy this winter.

I'd be curious to hear what unusual cover crops our readers have been trying in their gardens.  Be sure to mention your garden conditions and how well the plants grew in your comment so someone else can learn from your experience!