Generally speaking, there are only two ways to get keys:
- Zombies sometimes drop them when killed
- You can spend money to buy them if you tap a gate you don’t have the keys to unlock
Getting a zombie to drop a key is relatively rare, sadly. You’re going to have to fight a lot of zombies in order to get more. I’ve seen perhaps one every solid hour or two of play. If you need to get more stars, you can use getting stars as a good opportunity to grind zombie kills for keys. Related Guide For more info about stars and how to earn them, visit stars guide..
Plants vs Zombies 2 Keys: Fastest Keys
The “fastest” way to get keys depends somewhat on how much time you have to play. If you have a lot of time to play, grinding zombies is probably your best bet. However, if you don’t, there is another way to earn a bunch of keys at once. I’m speaking of the Treasure Yeti!