do they have a unwritten sell by date or shelve life ?
Reeds are essentially dead grass and they're not going to get any more dead by time passing.
Now I have more reason to keep playing synthetics... at least I know synthetics shouldn't go zombie on me :-/
Nope. Note if they're kept cool, dark and dry. Reeds are essentially dead grass and they're not going to get any more dead by time passing.
On the other hand, if they get damp, have temperature fluctuations, too much light, etc, they may warp, go mouldy, or whatever. And eventaully, just like all natural things, they will start to decay, but if they're kept in a cool dry dark place they will last for decades.