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