Originally Posted by
Mothership
Bloom & Doom quick guide
1. Start quest "Someone setup the pumpkin bomb"
2. When you see the game field Alt+f4 or have 2 wows open and login from the other.
3. Pickup sunpower untill zombies starts to spawn. If they wont start to spawn after 30sec just leave vehicle and start again (this wont reset your progress).
4. Don´t plant anything just wait and let them walk towards the FERTILIZE-O-TRON 2000 and they will get killed. You will get 1st wave complete from the 3 first ghouls and 2nd wave from the a bit bigger ghoul what looks like DK pet. If the bigger ghoul spawns on a line where FERTILIZE-O-TRON 2000 is consumed already just exit the vehicle, you wont always get 2 waves from one try because of the RNG. You can see how many waves you have done on the current try from the 0/7 meter above your hotbars.
5. Start quest again (no need to abandon the failed quest before) and repeat steps 1 2 3 4 and about 8-15 tries later you will get the achievement.