Built in 1873 this building served originally as a root cellar. The Sandburg's used the greenhouse side to start plants for the flower gardens and occasionally stored bulbs in its cellar.
Adjacent to the greenhouse, the Sandburg's cleared up to an acre for a vegetable garden. The garden provided much of their own food for the year through canning, drying and preservation. Still used each year to pant a variety of vegetables, this garden retains a strong association with its past.