Plants vs. Zombies Cheat: Unlimited Money
Once you have the Zen Garden, water the plants until they don't need anything else. After that, change the Date on your PC to another day. As soon as you do, the plants will need water again. Repeat this -- buy new plants, grow them to full size, sell and repeat to earn money.
This also works to get Marigolds in Crazy Dave's shop when they are out of stock. You can fill up your Zen Garden and make all the money you need. You don't even have to close out of the game.
Additions by dragonfellow17
Plants vs. Zombies Unlockable: Costumes
Enter these codes with your keyboard during gameplay for the desired effect:
* future - Futuristic sunglasses for zombies
* mustache - Zombies with stylish womb brooms
* pinata - A shower of candy when a zombie dies
* trickedout - Alternate Lawn Mower appearance
* sukhbir - Toggles the zombie's call for brains-sound
* daisies - Zombies leave small daisies behind when killed
Plants vs. Zombies Hint: Switch Locked Seeds
Tired of being stuck with the crappy cards Crazy Dave makes you have? All you have to do is exit the game and restart it and the 3 cards will be changed to something else.
CREDITS:
http://www.cheatscodesguides.com/