Board Thread:Plants vs. Zombies 2: It's About Time/@comment-24508466-20140216121036/@comment-4417029-20140429163924

I'm struggling with the third star challenge of level 3 in KF World. I can't balance between defeating zombies for 10 seconds and do not spend sun for 100 seconds. It's really hard without obtaining the Bonk Choy.

So, any good strategy?