Homemade heater: large terracotta plant pot (need the hole at the base for air flow), class jar , vegetable shortening and wick candles . , The candle heats the terracotta pot, thus heating the Amazon's wasteful packaging redeems itself by serving as winter insulation for outdoor potted plants. Ugly, perhaps, but it's winter, so who cares? : r gardening Boxhill Italian Terracotta Column Pot Handmade Clay Boxhill & Co., LLC Chain Link Fence Allows Potted Plants Purple Vine to Climb Up