Just today I gave my usual gardening reminder to several folks, and I figured I should probably post it here. Botanical fluids EXPIRE. The lifetimes are different for different things, and you can look them up, but you MUST MUST MUST write the purchase and or first opening date on the bottle. If you don't do that, and don't have a flawless memory, you never really know if your insecticide, fungicide, and even fertilizer are potent. You buy it, you mark it. It's that simple.