will grass seed go bad?

Different seed will be viable for different lengths of time. 5 years may be pushing it for most seed, but you might be fine with any rye grass portion.

Only one way to find out.

Most seed companies are saying 2-3 years.

Magoo61 wrote: ↑ Most seed companies are saying 2-3 years.

Plus storage conditions affect the viability of most seeds (heat and moisture). A germination test can be done using a damp paper towel inside a ziploc sandwich bag...sprinkle in a set number of seeds and see how many sprout.

I didn't even know they would go bad. I still have a couple unopened bags in my storage........

Good question.

Ideally, the seed should be used in 12-18 months. If using beyond that time frame, apply more liberally, as you may get a lower germination rate. If stored in ideal conditions, some ryegrass seeds may still be viable for up to about 5 years.

It looks like I should return some seed I bought. I bought 18kg, total but only ended up using about 5kg. At most, I'll use another 8kg by the end of next spring.