Plant Food

Plant Food is an item in Plants vs. Zombies 2: It's About Time and Plants vs. Zombies Online that gives plants more powerful effects. It is obtained by killing glowing green zombies, planting on Power Tiles in Kung-Fu World, breaking tombstones with a Plant Food symbol in Dark Ages, spending 1000 coins to get one, or planting a Power Lily (which must be purchased with real-life money to unlock). The player can carry three at a time at first, but an upgrade obtained in Ancient Egypt can increase this to four at a time; it can then be increased to five at a time via an in-app purchase. The player's current amount of Plant Food is represented by the lights on a bar at the bottom of the screen. Note, however, that the effect is temporary for most plants, and plants will then return to their normal forms (the exceptions include the effects to Wall-nut, Tall-nut, Pea-nut, Torchwood, Sun Bean, Infi-nut, and Hypno-shroom, which change appearance, and anything which duplicates, such as Potato Mine, Chili Bean, or their imitated forms).

A lesser known function of Plant Food is its ability to speed up the recharging of seed packets - when a plant food is dragged on top of a seed packet that is still recharging, it instantly becomes available for use. This can be especially useful for obtaining essential plants in emergency situations, such as instants, overcoming their (very) slow recharge.

These listed plants do not have a Plant Food effect because they activate instantly and disappear afterwards:
 * Grave Buster
 * Cherry Bomb
 * Jalapeno
 * Blover
 * Power Lily
 * E.M.Peach
 * Tile Turnip

Trivia

 * In the Chinese version of Plants vs. Zombies 2: It's About Time, the Plant Food is a bean instead of a leaf.
 * When Kung Fu World was released, The leaf icon appeared as an energy mechanism image.
 * The energy mechanism was removed in the latest update.
 * Plant Food somewhat resembles an atom.
 * When Plant Food is used on a damaged plant, it is restored to full health.
 * There is no reward to save Plant Food after the level ends, except in Endless Zones, in which the saved Plant Food can be used in next level.
 * While the plants are shining (using Plant Food), nothing can destroy them, to the point where they are immune to shovels.
 * Lightning Reed can get eaten because the invulnerability caused by Plant Food lasts 0.5 seconds.
 * When the Threepeater is using its Plant Food ability, the pattern the peas make resembles a leaf.
 * If the player digs up a Chili Bean or Potato Mine that was created via Plant Food, sun will not be given if they have Shovel Boost Upgrades.
 * This may be because the player did not plant the extra Potato Mines or Chili Beans, because the Potato Mine or Chili Bean that was fed with Plant Food was the ones who created the extra.
 * In the Zombot Dark Dragon's dialogue, it has been said that Plant Food is made out of zombies.
 * Penny later proved that Plant Food is not made of zombies.