Clean
Round up all your tools, a bucket of warm water and a wire or stiff bristle brush. Start with the brush and knock off the majority of the dirt on your tools. Once you have the dirt removed, scrub the remaining of with the warm water. Then rinse and let them air dry or wipe them with a towel.
Sand
Once your garden tools are dry, it’s a good time to sand any wood handles. Moisture, whether it’s from water in the soil, dew or rain will raise the grain of the wood, making it feel rough. Gardeners that live in high humidity regions will also see/feel this “grain raising” more often. Just about any sandpaper will work for this, but I suggest starting out with an 80 grit paper and finishing off with a 120-150 grit for a nice smooth handle surface. Also, now is a good time to take care of any rust on your tools. A wire brush is a good option for knocking off the majority of rust, especially in those tight spaces, but you’ll find that the 80 grit sandpaper will do a better job. If you have a small electric sander, this process will go a lot faster.
Sharpen Tools
Use a metal file to lightly sharpen the edges of tools. Again, you don’t want to grind away too much of the metal, just use it to smooth out nicks, remove burrs, and give a nice clean edge. On some cutting tools (like hedge clippers and axes), you’ll need to follow up with a sharpening stone lubricated with oil for a finer edge.
Oil
Using a clean rag, apply lubricating oil to both the wooden handle and the metal blade. Rub the oil into the surface then wipe off any excess. The oil will help prevent rust and condition the wood to keep it from absorbing water and prevent cracking. After the handle has dried, apply a second coat of oil to the wood if needed. Tools with fiberglass or composite handles will only need a good cleaning. Avoid using petroleum products, such as motor oil, because the next time you use the tool, you’ll be introducing petroleum into your soil.
Some gardeners prefer to sand wooden tool handles and reapply a coat of exterior finish such as spar varnish. If you do refinish your tool handles, make sure the wood is completely dry first. I prefer using oil simply because I’d rather do a quick wipe down, rather than taking the time to sand the wood, apply finish, and wait for it to dry, but it’s really a matter of preference.
Storage
Store tools in a dry, well-ventilated shed or garage. Smaller hand tools can be stored plunged into a bucket of sand or small pebbles, and larger tools should be hung or stored upside down so as not to dull their blades.
Disinfecting Wipes
Keep disinfecting wipes handy to remove sap, bacteria and fungus for a quick clean-up on the fly.
Preventing and Removing Rust
Making sure tools are dried thoroughly before storing and treating them with linseed or mineral oil are the best ways to keep tools from getting rusty. But, if you do discover some rust on your tools, here’s what you can do to get them back in working order:
Soak in a 1:1 mixture of vinegar and water overnight.
Scrub in a circular motion with steel wool.
Rinse in soapy water, and then plain water.
Let dry thoroughly, then rub lightly with linseed or mineral oil.
That’s it, protect your investment in garden tools and they will last a very long time.