Flower Pot

A flower pot is a decorative block that allows saplings, mushrooms, flowers - including the ones added in -, cacti, ferns, and dead bushes to be placed in it. Plants that cannot be placed in a pot are: normal tall grass, wheat, vines, lily pads, pumpkins, melons, nether wart, sugar canes, potatoes, carrots and two blocks tall plants. If the block beneath a flower pot is removed, it will break and drop itself and the plant it contained.

Flower pots can be placed on upside-down slabs and upside-down stairs. They can not be placed on normal slabs and stairs. When aiming at the side of a transparent block behind or above a crafting table the pot will not be placed on said block but on top of the crafting table instead. The same method works for furnaces and dispensers, but not for fences, cauldrons or chests. The flower pot is 3/8 block high and can be stepped on. It is not possible to walk from the top of a flower pot onto a full sized block without jumping. Despite appearing to have Dirt in them, they do not require Dirt to craft.

Natural Spawning
Flower pots have been known to spawn in witch huts usually containing red mushrooms. This is not the best source in the game, though, as witch huts spawn only rarely.

Trivia

 * The flower pot is based on a suggestion from Reddit, like Ender chests and Item Frames.
 * When placed in a flower pot, cacti will not harm the player or destroy items.
 * Flower Pots break falling sand and gravel blocks, much like torches.
 * Like cake and hoppers, flower pot has circular shape when viewed in the inventory, but has a square shape when placed.
 * Cacti in flower pots appear to grow on soil, although cacti can normally only be planted on sand.
 * Although bricks and clay are available in Pocket Edition, flower pots cannot be crafted using the MATTIS crafting table.