There are 756 lost seedlings, located in the following levels.

Level 1: 9 seedlings.
Level 6: 71 seedlings.
Level 9: 160 seedlings.
Level 10: 50 seedlings.
Level 12: 60 seedlings.
Level 14: 100 seedlings.
Level 17: 49 seedlings.
Level 18: 105 seedlings.
Level 20: 152 seedlings.