Germination

To germinate, a seed needs 3 things:
           - water
           - oxygen
           - right temperature

Germination is the sprouting of the seed. The seed swells from intake of water, and the outer coat begins to soften. After the coat breaks, the radicle appears and grows downward due to gravity.

Water - is required for germination. Mature seeds are often extremely dry and need to take in significant amounts of water, relative to the dry weight of the seed, before growth can resume

Oxygen - is required by the germinating seed for metabolism. Oxygen is used in aerobic respiration, the main source of the seedling's energy until it grows leaves.

Temperature - affects cellular metabolic and growth rates. Seeds from different species and even seeds from the same plant germinate over a wide range of temperatures.