Crazy Dave: Peashooter is barbecuing - is it feeling cold? Penny: Wrong! Peashooter's projectile passes through Torchwood to form into deadly fire peas!
Crazy Dave: Wow! I want to eat a double-layered beef taco right now!
Penny: Just temporarily forget about that! I found some gems, buy a Plant Food for backup!
Penny: Yes! I'm giving you the gems! Why? Because I'm crazy~!!
Sandstorms, Pharaoh Zombies, and high concentration of zombie hordes contribute to the difficulty of this level. Mainly, the newly discovered Pharaoh Zombie. This zombie has a high amount of health, and once the sarcophagus is broken, the zombie within comes storming out with a fast speed. This zombie acts similarly to Newspaper Zombie, but with more health. Instant-use plants are recommended to deal with the Camel Zombies and Pharaoh Zombies. However, an instant will only break the sarcophagus, letting the zombie free without harm. The pre-selected Torchwood and Peashooter will be a great duo on dealing with Pharaoh Zombies.
Do what you did in Day 5, but build 2 columns of Sunflowers instead of one, and use Peashooter as your main attack.
Plant Torchwoods in front of the Peashooters to deal double the damage made by them. Defend them with Wall-nut if needed.
To deal with Pharaoh Zombies, use or Peashooter's Plant Food ability (after planting a Torchwood in front of it) or Potato Mines. One thing you need to know is that Pharaoh Zombies needs two instant-kill plants to be killed, since the sarcophagus absorbs extra damage from projectiles.