Urban farming kits have appeared on our virtual pages numerous times over the past few years, including offerings targeting herbs, beekeeping and chicken farming. And while we haven’t featured kits for growing mushrooms on logs (which are popping up in stores and at markets everywhere), we were intrigued by a new, greener option that doesn’t require stumps of wood. California startup Back to the Roots now offers a grow-your-own mushroom garden kit that can be kept inside on a windowsill. Consumers need only moisten their garden twice a day with a provided mister, and within seven days a growing mushroom garden should be apparent. From there the mushrooms typically double in size each day, eventually amounting to a pound of produce per crop, Back to the Roots says; between two and four crops per kit can be expected. Perhaps best of all, though, is that Back to the Roots’ mushroom gardens use soil — provided as part of the kit — that’s made up entirely of recycled coffee grounds. The Easy-to-Grow Mushroom Garden is priced at USD 19.95. Five percent of sales are donated to support breast cancer research. Back to the Roots first launched its mushroom-growing kit in March at the Whole Foods in Berkeley, Calif.; since then, it’s expanded nationwide into nearly 100 other Whole Foods Markets as well as nurseries and science stores. Just last month, it was named an Innovation Award Winner by the Social Venture Network. Eco-minded retailers around the globe: this one’s for you!