Here is the full list of all 14 Flower achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Play the game after a week long break.
Bloom 10,000 flowers.
Journey to the city unscathed.
Use the grass as your canvas and paint the ground with three different colors.
Reminisce for three minutes before returning to the room.
Release all of the names to the sky.
Beyond all flowers lies another room.
Completely awaken the city.
Light a darkened pool.
Take a ten minute break between any dreams.
Play with the windmills and ride the wind seven times.
Life could be simple...
The dream has just started...
Find and bloom a secret flower.