If the game is still driving you crazy, here are some cheat codes that will make the game 
easier. Simply type these codes at any time during the course of the game:

Code          Result
--------------------
Goodtime    - Market demand will increase
Rain        - Plants no longer require water
Greenfinger - Plants grow very fast
Fund        - Gives you $100 each time you enter this code
Shopper     - All items will be unlocked in the shop

To deactivate cheat codes "rain" and "greenfinger," simply retype the code. 
The rain cheat code will wear off around three days