You don't "fast track" plant growth. You just provide the proper conditions for them and they will do the rest. Adequate water is often the governing factor on how well plants establish and start to take off, all other conditions being equal.

Couple of things you should be aware of. Excessive fertilization does not speed up growth but can lead to weak growth that cannot tolerate climate extremes and that is more prone to pests and diseases. And contrary to popular belief, Epsom salts does nothing for plant growth unless the plant is suffering from a magnesium deficiency.

The Myth of Epsom Salts