Whenever you've fully raised three different kinds of plants in the greenhouse you'll be able to use sunshine to increase the greenhouse's level. Once the greenhouse has reached its highest possible level you'll be able to attract a cute mystery creature to come join you in your greenhouse!

Just keep opening Plant Nanny² every day and you'll be able to get the sun as a reward for logging in. Or, you can watch an ad by clicking on the ladybug on the main page. You can only get 1 sunshine each day.

You can go to the Records page (2nd button from the left on the bottom) and check the X Consecutive Days Logged In reward to see how many days in a row you've opened Plant Nanny².