Then your garage, like mine is a chemical disaster waiting to happen. Now, I'm not about to tell you that it's time to clean out your garage-just your chemical storage area.
Many chemicals change over time, losing their effectiveness.
Unfortunately, most garden pesticides, fungicides and weed killers are classified as hazardous waste, and you can't just chuck them in the trash, or pour them down the drain. You can wrap empty containers in newspaper and put them out for collection, but those mysterious, half full fellows need to be taken a Hazardous Waste Collection Center in your area. Meanwhile, back to your garage. You didn't buy those cans and bottles just to sit on shelves. You bought them to use.