Lawn

The Lawn is where the player fights against the zombies, and is located in front of the player's house. Although the term is used to refer to the Pool, Fog, and Roof levels by most players in addition to in the song Zombies on Your Lawn, these places are technically the backyard and roof of the player's house, and the lawn is just the front yard.

Layout
The Lawn is arranged in a grid with nine columns and five rows (in the Day, Night, and Roof stages) or six rows (in the Pool and Fog stages) that the player can plant on, one plant per square. During the Night, squares can also contain Graves where the player can plant nothing but Grave Busters and from which zombies emerge during the final wave. Also, the use of the Doom-shroom creates Craters in the lawn which cannot be planted in.

How It Works
Zombies approach from the right side of The Lawn, and eat the player's Brains if they get through his/her defenses. In the first two stages, which are in the Front Yard, and the third one which takes place in the backyard with a pool, the player has Lawn Mowers which run over all the zombies in a row, or lane, completely destroying them. However, they can only be used once. Later, in the pool stage, the Lawn Mowers by the pool will only kill the Zombies that have made it out of the water at the time, so it is recommended to buy the Pool Cleaners (which kill all of the pool zombies in a similar fashion to that of the lawn mower) as soon as possible. On the Roof, there are no extra defenses until the player purchases the Roof Cleaners from Crazy Dave's shop. All of these remaining at the end of the level provide an extra gold coin (worth $50) each.

Trivia

 * If you look closely at the lawn, you can see tiny red and yellow flowers in the grass.
 * There is a Night Roof Layout that is only playable on Dr. Zomboss's level.
 * The lawn varies in size in certain levels (in the first 1-1 it is only one lane, in the first 1-2 and 1-3 there are three, and the backyard has 6 lanes instead of the normal 5 in the frontyard).