Locate a spot that stays well-drained in your yard, especially after rainy weeks. The ideal place will never be covered with puddles and the soil will stay firm after any storm.
Dig a hole in that spot that matches the size of the garbage can. The can's opening should stand about 4 inches above ground level. Use the excess dirt to build a 6-inch to 12-inch mound surrounding the opening. Dig a shallow drainage ditch surrounding the mound and extending away from the hole, preferably down a hill.
Place the stones in the drainage ditch to prevent blockage by leaves or small sticks. Position the stones so water can pass under them in the ditch.
Place the garbage can in the hole, and fill in any extra space between the can and the hole's wall with dirt.
Place the root vegetables inside the plastic bags and gently place in the garbage can.
Place the lid on top of the garbage can, cover the lid and mound of dirt with straw and cover the straw with plastic sheeting. Store the vegetables until you need them in your kitchen.