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