Board Thread:Plants vs. Zombies Wiki Discussion/@comment-4009269-20140213201430/@comment-7234182-20140710165910

Balam Ajaw wrote:

Also there is a more complicated Zen Garden or something like that:

That's not a more complicated Zen Garden. It's a progression system which grants plants some unique abilities as you level up the plant.

For example, Twin Sunflowers when upgraded to level 2 will give you 25 sun immediately after being planted, at level 3 it gives even more sun, potato mine's arming time decreases, offensive plants shoot faster, and so on.