Water, Weed, and Wait by Edith Hope Fine and Angela Halpin (2010)

When Miss Marigold challenges the kids at Pepper Lane Elementary to turn an unpromising patch of their schoolyard into a garden full of fruits, flowers, and vegetables, they know they’ll need all the help they can get. Soon everyone in the community is lending a hand—including an unlikely neighbor with a soft spot for gardening—and it isn’t long before peppers, zuccchini, sugar peas, snapdragons, zinnias, and much more are growing and blooming.