Many nationwide home and garden stores, such as Lowe's and Home Depot, carry large flower pots. Local nurseries often carry large pots and planters as well.
To find stores that sell large flower pots, check the websites of local home and garden stores. Some stores, especially local nurseries, may not display updated inventories online, so call these stores to find out if they sell flower pots and the sizes of those pots.
Large flower pots are available in many colors, patterns and materials. The cheapest flower pots are plastic, while more expensive pots are made of wood, metal or ceramic.