According to the Garden Illinois, moisture is a key ingredient needed for germination. However, too much moisture causes grass seeds to rot. Once you begin watering the seeds, they must remain moist for germination to take effect.
Temperature is another important factor in grass germination. Warm season grasses will not germinate until soil temperatures get above 50 degrees Fahrenheit.
A third key factor for germination is oxygen, according to Ohio State University. Before the embryo begins to grow, oxygen is needed to break down the food source that is stored in the seed. Using soil that is well-aerated will help oxygen reach the seed easier.