Hi, Well I recommend cleaning and sharpening all your garden tools at least once a season. If you have a lot of large tools you can bill a box with sand and pour in some used motor oil. Then, you just need to plunge the working end of your tool into the sand at the end of the season to keep it clean and rust-free. The same goes with hand tools. With pruning equipment you need to sharpen it frequently to keep it in top order. A file should work fine. Also, I highly recommend stainless tools if you can find them. I have a stainless spade and garden fork that stay clean easily with just a wash from the hose. I also use a stainless trowel.