1. Freed up about 232+ mb of my system storage (had to backup the .apk files using App 2 SD and uninstalled almost all apps I had). I can install them later when needed anyway. Basically only PVZ and the launcher are the installed apps.
2. I used VTL Launcher. I'm not sure if Zeam launcher will also work. (Lesser home screen pages and widgets/icons probably affected memory. The stock launcher did not work for me.)
3. Closed all other apps (except the launcher) in System Monitor to free memory.
4. Removed the live wallpaper.
Those sound like they could be possible causes for people having trouble with this game.
1. I have UrukDroid installed so I have plenty of system storage so this may be the case with people having issues.
2. I am using Zeam launcher, so stock launcher may be issue as well.
3. I did not use system monitor or any other memory manager, Not sure if I have swap or compcache enabled
4. I never use live wallpaper