Not sure what help the magnesium is to the formation of the buds, Prabhi.
Ursula's diagram above shows that magnesium is an essential element for plants to form chlorophyll, and chlorophyll is the green pigment in leaves that allows the plant to collect the sun's rays and produce sugars as food for the plant.
So, really plants can use a steady supply of magnesium, not just when they are starting to bloom.
