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