You can also integrate 9990 sunshine before the second level. Only lotus leaves, cattails, watermelons, frost watermelons, nut walls, imitators: nut walls, potato thunder, cherry bombs, sunshine flowers. Spend 200 yuan to buy a shovel (effect: it can kill the first zombie who comes).
After you start, just plant sunshine flowers, anywhere. After the first zombie is killed by a shovel, put a potato mine (I found this is a bug, where you put it, there will be zombies), and the second one will still put a potato mine (it is best to wait until the zombie appears at this time) (as many flowers as you can put before). Then just wait for the sunshine of cattail to come, and pack one, just two. Then plant a nut wall and plant it in the third row. Then you can plant frost watermelons in one row above and below the lotus pond (if necessary, you can plant watermelons in both rows). After that, just plant sunshine flowers everywhere behind the nut wall (except cattail and watermelon). Almost like this, the first round can charge 5000 yuan, and the second round can charge 9990 yuan.