So it seems that if I buy one of the weed sprays that screw on the end of garden hose, and don't use it all up In the season I bought it, that come next summer that it doesn't kill the weeds. At best, it just kinda stunts their growth. If I then buy a new sprayer, it works great. So, I am wondering it it is how I am storing it, or is it just that there is an expiration date, which isn't listed anywhere? I have been keeping it in a wood cabinet in my garage, which rarely, if ever, gets cold enough to freeze water. Would it help if I put it in my basement? Label says store in cool dry place.