Flower Pot

The Flower Pot can be only planted and is required on the Roof levels, because it allows you to plant other plants on the roof, similar to the Lily Pad on water. Even though it is for planting on the roof, it can still be planted on the front lawn, but not on Lily Pads for some strange reason.

Suburban Almanac Entry
Flower Pot

Flower Pots let you plant on the roof.

Special: allows you to plant on the roof

"I'm a pot for planting. Yet I'm also a plant. HAS YOUR MIND EXPLODED YET?"

Cost: 25 Recharge: fast

Usage
Plant it on the Roof, and then put a plant in it. Flower Pots cannot attack, and do not have any point outside of the roof levels, but have just slightly above the normal amount of resistance to chewing. To plant any explosives like Cherry Bombs or Doom-shrooms on roof levels, a Flower Pot is still required. If a Doom-shroom detonates on top of it, it is destroyed and a crater appears in the roof. The strongest anti-zombie barrier in the whole game is when you plant a Flower Pot, a Pumpkin, and a Tall-nut together, which will hold a zombie for upwards of four minutes (longer when the zombie is frozen or there is a Kernel-pult in the same row).

Note: This isn't as sun-efficient as just a Tall-nut or just a Wall-nut, though the latter can be vaulted/jumped over, and the single Tall-nut setup can be hard to maintain due to its long recharge time.

Note: Spikeweeds and Spikerocks can't be planted in pots, nor can Grave Busters, because Graves don´t appear on the roof.

Strategy
You can use it to slow down Gargantuars in emergencies and to make Pole Vaulting Zombies lose their poles, or to provide a few extra seconds before the zombies get to your defenses in levels such as Column Like You See 'Em. Otherwise, use it to plant on the roof. If you want to slow down zombies on the roof, a combination would be a puff shroom (by itself) or wall/talll-nut on a flower pot coated with a pumpkin (which gives a three-layer defence).

Trivia

 * On the first roof level you will be provided with 5 flower pots on each row. You will be provided with four Flower Pots on each row in the next level, and the rest of the roof levels would have three on each row.
 * The Flower Pot is one of the two plants that can appear even before it is planted, the other is the Sunflower (in Versus Mode).
 * The Flower Pot is the only plant in the Suburban Almanac with a Roof background. This may be due to the fact that it is essential and more commonly used in this area.
 * The Flower Pot is actually a plant itself, according to its Suburban Almanac entry.
 * If you look closely, there is a sprout with leaves on the Flower Pot, further proving the point that it is a plant. However, the Flower Pot in the Zen Garden does not have the sprout, showing that it is a regular pot.
 * Also, if you look closely on the vase, you'll see what looks like two closed eyes and a mouth.
 * The Flower Pot cannot be put in the Zen Garden unless the Player has a Zen Garden Editor. This may be due to the fact that it does not make sense to have a Flower Pot inside a Flower Pot.
 * It is also the only non-upgrade plant besides the Imitater that can't be obtained into your Zen Garden.
 * Flower Pots are the only plants that can be planted directly on the roof.
 * Maybe it's because the fact that it is a Flower Pot, it does not have any roots.
 * The soil in the Flower Pot darkens like it is watered when you plant a plant in it.
 * The Flower Pot can be planted on the grass, but it is unnecessary unless you want an emergency-delay plant.
 * The Flower Pot is the only plant (excluding Imitater) which can be planted in multiple areas (Lawn, Roof) without the help of other plants.
 * An Imitater Flower Pot, when planted, will obviously have gray color. But when you plant on that Imitater Flower Pot, it will turn orange, which is its original color. However, if you remove that plant, it will turn gray again.
 * In the Xbox 360 trailer, the Flower Pot is half-shown on the Roof.
 * Flower Pots are only recommended only for Roof Levels.
 * The Flower Pot is one of the three plants that are not recommended in Fog Levels, the other two being the Coffee Bean and the Grave Buster.