Though the terms “planter” and “pot” tend to be used interchangeably when referring to a growing container, there are a few differences between the two. A pot is usually rounded, made from an earthenware material, and does not have drainage holes in the bottom. A planter is typically rectangular, made from any of a variety of different materials, and has holes for drainage.
Planters and pots can be made from the same materials, and many planters are made from clay, stone, terra cotta, and other materials usually associated with pots. Pots, conversely, may be made from iron or metal, but anything made from wood, plastic, or fiberglass is generally considered a planter. A good rule of thumb when trying to distinguish between planters and pots is that if you could theoretically cook in it over a fire, it is a pot.
It can be difficult to tell the difference between planters and pots based solely on finish. Both can be either glazed or unglazed. Planters are usually designed to withstand outdoor conditions, while pots are mainly for decoration and may crack in harsh conditions.
Pots are generally thought to be round, though square pots do exist. Planters tend to be long, narrow, and rectangular, though they are also made in round and square shapes. Hanging baskets and cones are considered planters, not pots.
Gardeners use the term “pot up” when referring to the process of transferring tiny seedlings into plastic, rectangular growing flats, but these flats are actually considered planters, not pots. Adding to the confusion are a great number of gardening catalogs, publications, and garden suppliers who use both “planters and pots” in their descriptions of similar products.
The drainage holes are the best feature to use to differentiate pots from planters, although garden supply companies often add a hole or plug to the bottom of pots to make them more versatile. A pot is not necessarily designed to hold a growing plant, hence the lack of holes, though it is common for gardeners to place a planter inside a pot. The holes in planters indicate that they are specially designated for growing plants. They also tend to have more plant-friendly shapes. Some planters even have self-watering capabilities, with built-in reservoirs designed to catch water and slowly disperse it to roots.