Gumdrop Tree Centerpiece 18-inch Styrofoam cone 1 bag large green gumdrops 1 bag small gumdrops, assorted colors Toothpicks Secure large gumdrops to the Styrofoam form with the toothpicks. Arrange the small gumdrops in between the large ones to hide the Styrofoam form. The trees are pretty on mantels or arranged near gingerbread houses.