This is my strategy for earning tons of money in Plants Vs Zombies if you only have 9 slots. You need to have finished the Adventure mode and at least 13 mini-games to play Last Stand mini-game.
Stage 1 should look like this, 50 suns remaining. At Stage 2 save suns to rebuild new garlics and Wall-nuts.
Plant collection setup (for 9 slots)
- Stage 1: 1,420
- Stage 2: 1,440
- Stage 3: 1,210
- TOTAL: 4,070
This is from the first record although I’ve gathered up to 6,000.
This tactic is optimized for players with 9 slots. If you have 10 slots look for a better tactic since you will be able to have Pumpkins which will help a lot to get to the next stages.