Wall-Not Attack

Strategy
This Achievement is a little hard to beat, since defensive plants are a must in this mini-game, as Peashooter Zombies can attack from afar. But with the right strategy, this Achievement will become easy to earn!

Choose the following plants:
 * Sunflower
 * Twin Sunflower (Optional)
 * Potato Mine
 * Imitater Potato Mine
 * Squash (Optional)
 * Spikeweed
 * Spikerock
 * Coffee Bean
 * Fume-shroom
 * Gloom-shroom
 * Garlic

Buy the Rake as well.

First, plant Sunflowers in in the first, third and fifth lanes, but if there is a rake on it, don't plant anything in that row yet. Then, when the second zombie comes, use the Garlic to divert it, then, use the Potato Mine. Repeat this and lay down double garlics in the first, third and fifth lanes until multiple zombies come, then start laying down Spikeweeds and Spikerocks. Then once you can afford it, plant Gloom-Shrooms on lane three behind the Garlics. Once you have a row of spike plants on lanes 2 and 4, plant three Gloom-shrooms on lane 3 behind Garlics, you should do fine. Remember though, regularly replace Garlics if they are nearly fully eaten.

Alternatively, you can use the Squash in addition to the Potato Mine and Imitater Potato Mine to earn a decent amount of Sun first. Spikeweed and Spikerock should be sufficient to fight off the zombies, if you do not have the Gloom-shroom. If you find you have Sun to spare, you may also plant Twin Sunflowers to get more Sun, possibly also earning you the Sunny Days Achivement.

Another strategy is to select the following plants:


 * Sunflower


 * Garlic


 * Potato Mine

And any other shooting plants.

First, plant Sunflowers on the first and fifth lanes, and put Garlic in front. Use the Potato Mines to kill the zombies. Then put the Garlic in front of the other lanes, as they can withstand a fair amont of damage. Then put your shooting plants behind the Garlic. Remember to replace the Garlic.

Another strategy to try is to get the achievement Pyromaniac at the same time. Bring the following plants:


 * Sunflower


 * Potato Mine


 * Imitater Potato Mine


 * Cherry Bomb


 * Jalapeno


 * Doom-shroom


 * Ice-shroom


 * Coffee Bean


 * Garlic

Start by planting as many Sunflowers as you can in the 1st, 3rd, and 5th lanes. Plant 2 garlics at the front of these to divert all the zombies into 2 lanes. Remember to replace your Garlic often, as they only need 16 peas to be killed. A single garlic can be killed by only 5 to 6 zombies. Plant potato mines ahead of zombies, as peas will pass over them. Use cherry bombs for small groups of zombies, Jalapenos for lanes full of zombies, and doom-shrooms for waves of zombies. Plant sunflowers, unarmed potato mines, and other cheap plants to hold off zombies long enough for a plant to recharge if you need to. Also use Ice-shrooms to hold off alot of zombies at once. Just be careful not to use any Lawn Mowers or Garden rakes, or you will not get Pyromaniac at the same time.

Another Strategy

Any other plants you will think will be useful. but never EVER put sun shrooms. you get more sun than it gives, and it requires a Coffee Bean, hence making it even more expensive. Some plants are small enough to dodge the peashooting zombie's attacks. For example, Puff-shroom they can easily take down peashoothing zombies. But the wall-nut zombies will need more.You can use a Doom-shroom or a Hypno-shroom. Using this strategy you may also get the Good Morning achievement
 * Puff-shroom
 * Doom-shroom
 * Hypno-shroom
 * Coffee Bean

Trivia

 * The Achievement's name is a reference on the Wall-nut.