Stack cake dummies (found in cake decorating stores or at www.cookscakeandcandy.com—search “Styrofoam dummy rounds”). Cut Styrofoam cone to about 4 in. high; glue on top of small cake dummy. Glue remaining cake dummies together. Wrap the form in cheesecloth dyed with food coloring.
Attach kale leaves with toothpicks. Add veggie trims.
For daikon radish garland, use a vegetable peeler to create long, thin ribbons from radishes. Drape around the tree, going under some trims and over others, and tucking in the ends to hide.
For ornaments, cut turnips into 1/4-in.-thick rounds. Use cookie cutters to make ornaments; attach with toothpicks.