Unopened grass seed may last longer than an opened bag, but how you store them makes a difference in how long the seeds will remain viable.
The rule of thumb for best storage conditions for grass seed is to calculate the sum of. and 70-90% RH, so anything in an outdoor shed is not going to last long.
I've kept some rare prairie grass seed for over 10 years in a ziplock – in a. If the seed is kept in a controlled humidity, cool environment they will be viable a lot long.. grass you're talking about and the method and the length of storage you put. What is the best way to keep birds from eating new grass and grass seed on .