Money

Money is used to buy items from Crazy Dave's Twiddydinkies. Before the shop is unlocked, it can be used to purchase seed slot upgrades directly from Crazy Dave, though you can only have up to 8 slots before the shop is unlocked after level 3-4. In most cases, money will drop under certain conditions, and the player must click on it, move the cursor over it or have a Gold Magnet collect it to obtain it, although it will sometimes be automatically added to the bank. (The player can't have more than $99999.00; once that amount is reached all money collected won't affect your total). Through cheating it is possible to get $999,999 and above. However, in certain GOTY versions, you can get above $99,990. Now in iPad version, player can earn more than $999,990.

Currency
There are three types of currency:
 * Silver Coins - worth $10
 * Gold Coins - worth $50
 * Diamond - worth $1,000

Earning Money
Money can be earned in several ways:


 * Killing Zombies (sometimes coins, diamonds, chocolate, or Zen Garden plants may drop), and killing a Zombie Yeti will drop five diamonds (four on later encounters).
 * Leftover Lawn Mowers, Roof Cleaners, and Pool Cleaners (they turn into gold coins after each level and are automatically collected)
 * Marigolds (they drop coins and occasionally diamonds at intervals)
 * Completing Levels (when Mini-games, Puzzle Mode levels, and Survival Mode levels are completed, a money bag or trophy is dropped; clicking on it will cause coins or diamonds to be automatically collected)
 * Eating Brains in I, Zombie (coins, diamonds, presents, or chocolate may drop)
 * Every few levels in Vasebreaker Endless (the last vase will drop a money bag)
 * Completing Adventure Mode levels after beating them for the first time (the last zombie will drop a money bag with 5 gold coins in it)
 * From Zen Garden Plants (Zen Garden plants drop money after being watered or fertilized, as well as after the Phonograph or Bug Spray is used on them. After the Phonograph or Bug Spray has been used, they also drop occasional coins in a manner similar to Marigolds.)
 * Destroying a Grave with a Grave Buster (coins, diamonds, presents, or chocolate may drop)
 * Selling Zen Garden Plants (directly adds a certain amount of money to the bank balance; this amount depends on the type of plant and its maturity)
 * Slot Machine (sometimes gives diamonds when spun)
 * Completing Adventure Mode will give you 3 diamonds

Trivia

 * In the UK, money bags, coins, and the dollar hedge on the leader boards (XBLA version only) will show pound signs but the currency will still be dollars.
 * It is unknown where the zombies get all of the money (although it is assumed that the money belonged to the zombie before they were zombified), or how it drops when they die.
 * It is possible that the money is located in the pocket, and when the Zombie dies, the coin falls out.
 * It is unknown how do Money stay perfectly fine after being exploded by Instant Kills.
 * The Silver Coin is common, the Gold Coin is uncommon, and the Diamond is rare.
 * In the iPhone/iPod Touch and iPad versions, the coins have a sun emblem instead of a dollar sign emblem.