As mention in the Start playing page, you should have planted your first seed. To gather two more seeds to complete this puzzle, you will need to have completed puzzle 6. As soon as a rain storm starts, grab an adult villager (again, not a nursing mom) and drop it on the lift. You will see at the bottom of the window "Standing on the lift". Leave the villager there until the lift reaches its highest point. A seed will then fall from the tree. Drop your villager on the seed and he/she will plant it.
- Notes
If you want to gather more seeds, they will be put in the food bin.
If you have trouble getting to the lift before it starts to go up, you may pause the game with when you see the rain start before finding a villager. You will need to unpause the game to see the "Standing on the lift" message to make sure they are properly placed.