In order to unlock the ability to buy garden plots, your home has to get to level 50, with a home value of $1,020,000.
1. It's what your friends see
Let's be honest, Sims Social is a competitive game, too. The one-upsmanship is definitely a part of the appeal. That being said, the figure your friends see beside your icon at the bottom of their screen is your home value. Not your total value.