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.
Beyond all flowers lies another room.
Journey to the city unscathed.
Light a darkened pool.
Use the grass as your canvas and paint the ground with three different colors.
Release all of the names to the sky.
Completely awaken the city.
Life could be simple...
Play with the windmills and ride the wind seven times.
Take a ten minute break between any dreams.
Reminisce for three minutes before returning to the room.
The dream has just started...
Find and bloom a secret flower.