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