Night

The Night area is the second stage of Adventure Mode and the setting of the ten levels after the daytime levels in Plants vs. Zombies. It is exactly like the Day levels in layout except that it takes place in the nighttime; therefore mushrooms stay awake and sun does not fall from the sky. Because of the lack of falling sun, it is much harder to defend the home without using mushrooms, and the player's sun producers have to be well-guarded. Sun-shrooms (25 sun) take the place of Sunflowers and Scaredy-shrooms (25 sun) take the place of Peashooters. Also, during this stage, graves will appear at the beginning of the level in random points on the half of the lawn farthest from your house. They cannot be planted on, and zombies surface from them during the final wave of a level. However, graves can be removed by Grave Busters and the Imitater Grave Busters. thumb|300px|right|The music to the Night stage

New plants
Nocturnal Plants, which mainly consists of Mushrooms, are the key to Night levels due to the lack of sun, and the fact that they generally require less sun than normal day time plants. The most important mushrooms introduced in these levels are the Puff-shroom which costs no sun at all which is helpful because of the lack of sun, however their short range means the player will eventually have to move on to better ranged mushrooms such as the Fume-shrooms and the Scaredy-shrooms, which are still both relatively cheap. The Sun-shroom, which costs less sun than the Sunflower, is also important. Sun-shrooms are vital as they are the only source of sun during the night (or Sunflowers if one was to decide to plant them). The other nocturnal plants introduced are Grave Busters, Hypno-shrooms, Ice-shrooms, and Doom-shrooms.
 * Puff-shroom
 * Sun-shroom
 * Fume-shroom
 * Grave Buster
 * Hypno-shroom
 * Scaredy-shroom
 * Ice-shroom
 * Doom-shroom

New zombies
An important trick for the Dancing Zombie is to use a Hypno-shroom on him as fast as possible to avoid non-hypnotized Backup Dancers. The hypnotized Dancing Zombie will summon hypnotized Backup Dancers, and this is extremely useful most of the time, albeit one should be careful not to hypnotize any Backup Dancers instead.
 * Newspaper Zombie
 * Screen Door Zombie
 * Football Zombie
 * Dancing Zombie
 * Backup Dancer

Trivia

 * The song played in this area is called "Moongrains".
 * Oddly, the song played during the Night level is the only one that changes drastically during the huge waves of zombies, with a change in tune and more instruments.
 * In Survival: Night levels, even in between huge waves, the music also changes, while in regular levels after a huge wave has passed, the music reverts to original.
 * It's unknown why there are graves that appear on the owner's front lawn every night. Some fans speculate it could be because of certain environmental factors such as the daytime rain in between the Night levels. Thus, graves don't appear in the day stages because there's no rain.
 * If you use a Hypno-shroom on a Dancing Zombie, you will get the achievement Disco is Undead and sometimes called Thrilling the Zombies.
 * Zombonis do not appear in Night stages because of the presence of graves; their Ice Trail would go under the grave but not smash it, which would not make sense.
 * In Survival Mode, at least one grave pops up before the last huge wave of zombies approaches, meaning it is impossible to completely remove the graves so they never come back.
 * If the right half of the lawn is full of plants, then one plant will be removed to make space for graves (graves do not appear on the left three columns).
 * Night is noticeably darker than fog.
 * This area has the biggest variety of One-Use Plants you will receive.
 * Sometimes there is a glitch in the Game of the Year Version where after the final wave appears, the music stops completely.
 * This is the only area with more than 10 stages in Adventure Mode, as Level 4-5 is a Night stage rather than a Fog stage.