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