Basic Botany

For those wondering how to play:
You need to gather sun light (the little orbs that fall) to increase your energy. When you gather enough energy, you can place a plant on the field to help your fight against the zom... undead. Sunflowers are used to gather more sunlight that can be collected, spitters are your primary offense in starting.

To gather sun, you right click them. For some reason I had to do this twice to get it to count per sun. If you find it isn't working, try disabling your addons.

The bottom will have a bar filled with your current options. When you've gathered enough sun, place your sunflower in one of the blocks that make up the lawn (better to have it in the back [left side], in order to give you more space away from oncoming undead.

Some really good tips here: plant at least 3 sunflowers before any offense. The initial undead are very slow, and can be killed easily. It's best to plant as many sunflowers as you can in this beginning time in order to have enough for the waves later.

I made videos of the entire chain. Here's a link on YouTube:

1. Basic Botany
2. 
   
3. Flower Power
4. 
   
5. Ghouls Hate My Grains
6. 
   
7. Someone Setup the Pumpkin Bomb
8. 
   
9. Lawn of the Dead

edit: added YouTube links to entire chain

this is the first quest of the plants vs zombies chain.
based on the popcap game plants vs zombies.
completing the chain will give you this: Don't Want No Zombies on My Lawn

the name of the achievement comes from the song. clicky