Costway 71" Large Wooden Planter Container with Trellis, Hanging Roof 4 Drainage Holes Modular Stack Planter by Angus & Celeste Mint Have you considered growing blackberries in containers? This is our second year of growing a thornless blackberry in a container, which is half of a 30 gallon drum. We have created a custom soil Master Garden 13" Plastic Blue Carved Design Planter