Q: I have been storing fertilizer in a galvanized garbage can with a lid in the garage. Is this safe?
A: If you are worried about explosive potential, I very much doubt homeowner fertilizers would blow up. Open containers of fertilizer do not lose nutrients but they do absorb moisture from the air, making them difficult to use in a spreader. If the fertilizer is lumpy, it can be broken apart with a hammer and applied by hand. My father took the “bulk treatment” route. He had me spread old fertilizer on a sheet of tin roofing and he ran over it with the family sedan!