Being living organisms, these seeds interact with the surrounding air and moisture, which can change their germination chances. Unopened grass seed may last .
Most grass seed I'm familiar with has a viability around 85% – meaning that if you. time, but seeds that are stored in a cool, dry place should last a long time.
Too much or too little, when watering new grass seed, can kill your lawn before it starts. Learn to. This is how long it will take to actually see the grass growing.