How long?

There is only one way to find out... sow them next spring! Personally, given that they have been kept in a polythene bag (paper would have been better) I doubt it but go try and good luck!

i reckon some of them will. it will be fun to try next year as mg says.

If it were me I would give them a go. Only time will tell but I wouldn't be surprised if some do well.

Thank you for your feedback. I've just joined, and what a nice forum this is! Thanks again, I'll certainly sow and watch to see what happens.

But buy a packet of fresh seed as well just in case!

moon grower gave you good info, seeds have been known to be ok for over five years but in paper bags, in plastic they swet and that is the end of them paper keeps them dry and most seeds will wate in that condition untill conditions are right to germanate damp and warm,