This is for after the Halloween update for free LP's:
1. plant crops, whatever kind with up to 10 sims and exit game.
2. go into settings, general, date and time.. change the date and year backwards (I always go back one month and two years)
3. exit settings, then double tap the home button. Press and hold down on the sims once it pops up until a minus sign appears and press it.
4. Hit home button, re-enter sims, wait a few seconds or minute until the game is all loaded, and exit again.
5. Go into settings, change date and time to automatic.
6. Leave settings, go back to the game and voila, 10 lp's and the crops are all grown. yay