Prisoners build an organic vegetable garden in the prison yard of the medium security unit at San Quentin State Prison in December. Kirk Crippens/ Insight Garden Program hide caption

itoggle caption Kirk Crippens/ Insight Garden Program

Hermine Ricketts says she gardens for the food and for the peace it brings her. Greg Allen/NPR hide caption

itoggle caption Greg Allen/NPR

The Nourishmat, which is inspired by Square Foot Gardening, makes it easy to grow 15 to 20 pounds of food in a small space with a plastic mat that serves as a garden planting guide. Courtesy of Earth Starter hide caption

itoggle caption Courtesy of Earth Starter

Decorated gnomes designed by celebrities, including Elton John (second from the right), are displayed at Chelsea Flower Show on Monday in London. Dan Kitwood/Getty Images hide caption

itoggle caption Dan Kitwood/Getty Images

Through the City Land Application of Biosolids Program in Geneva, Ill., the fertilizer supplement is provided to local farmers at no cost. City of Geneva/Flickr hide caption

itoggle caption City of Geneva/Flickr

An urban farmer waters his plants near Bamako, Mali, where the government has set aside nearly 250 acres for market gardens. donkeycart/Flickr hide caption

itoggle caption donkeycart/Flickr