Quick Guide

10-inch diameter pots holds two and a half to three gallons of potting soil. It's a great container size for succulents and herbs, as well as vegetables like leaf lettuce, strawberries, turnips, beets, small carrots, and flowers like marigolds and zinnias.

14-inch diameter pots work well for cabbage, peas, large carrot varietals, spinach, and hearty leafy greens like kale.

18-inch diameter pots can house large vegetables like broccoli, cauliflower, eggplant, courgette, peppers, and tomatoes. It’s also the perfect pot for growing berries, shrubs, cacti, and even dwarf citrus trees.

24-inch diameter pots hold 24 gallons of soil and can handle large houseplants with a somewhat extensive root system also provided the pot height is tall enough (tree roots need room to grow downward). 

30-inch diameter pots are massive by most standards, 30-inch pots generally serve as nursery pots for trees that will eventually go in the ground. Full trees including pear, apple, and plum can live their entire lives in a 30-inch pot, provided they’re properly fertilized.