How to Sharpen Pruners With a Sharpening Stone

Keeping your pruners working correctly requires regular maintenance.

When pruning a plant or tree, it's important to the continued health of the plant that your cut be a clean one. After being cut, the plant releases a liquid which coats the cut area, creating a protective covering that helps to heal the cut. By using sharp pruners you make the cut as clean as possible, speeding up the healing process of the plant and ensuring that it continues its natural growth cycle. Using a sharpening stone to sharpen a pruner's edge is a quick and efficient process. It only takes a few minutes to complete, but the extra time will save your plants and shorten the time it takes to cut them.

Things You'll Need

• Wrench
• Screwdriver
• Bucket
• Soapy water
• Stiff brush
• Cleaning solvent
• Lightweight motor oil
• Medium-grain sharpening stone
• Fine-grain sharpening stone
• Pruners
• Clean cloths

Instructions

1. Disassemble the pruners for easier handling. Remove the bolt or screw holding the two blades together using a wrench or screwdriver. Separate the blades once the bolt or screw has been removed to better access the full length of the blade.

2. Clean the blades of your pruner with soapy water. Dip the blades into the water and then use a stiff brush to remove any dirt, debris or rust from the pruner surface. Scrub vigorously at the blades using the brush to remove all extraneous materials. Rinse the soap off the blades using clean water. Remove sap by dipping the pruners in a solvent prior to scrubbing them. Allow the solvent to soak into the sap for three to five minutes and then scrub with the brush. When the sap is removed, scrub any residue of the solvent off using the soapy water and then rinse the blades in clean water. Dry the blades by patting them with a rag.

3. Wipe the blades with a light coating of motor oil, using a rag.

4. Examine the blades to determine which surfaces require sharpening and at what angle the sharpening stone should be applied. You can determine the surfaces and angles by noting previous sharpening marks on the blades. Previous sharpening will leave an edge that is shinier than the rest of the blade with notable scratches.

5. Use a medium-grain sharpening stone to begin the process. Soak the stone in lightweight motor oil prior to use so that it will slide smoothly down the length of the blade, using the oil as a lubricant. The oil also helps to carry away debris created during the sharpening process for a smoother edge.

6. Place the blade against the stone so that the previous edge is flat against the stone to create the proper sharpening angle. Drag the length of the blade along the stone, applying light pressure to the blade. Sharpen the blade from the blade's base to the blade's tip, always moving in a single direction. Drag the outside edge of the blade down the stone's surface 10 times, and then drag it once down the inside of the edge. Continue the process until the blade is sharpened, dipping the stone as needed into the oil to keep the surface of the stone wet.

7. Switch to a fine-grained sharpening stone to smooth the edges. Use the same sharpening process used with the medium-grained stone to produce a razor sharp edge.

8. Test the sharpness by holding the blade in front of a light source. If the light reflects off the edge, it requires more sharpening.

9. Finish the blade edge by applying a light coat of oil to keep dirt and moisture from collecting on the blades during use.

Tips & Warnings

• If the blade has been nicked, remove the bent metal part of the blade using a file.

• Never sharpen the blade to an edge less than 1 mm thick as the blade will be prone to nicks.

References

• Grounds Maintenance: How to Sharpen Pruners, Shears and Loppers
• PBS, The Victory Garden: How To Maintain Your Pruners
• Info Barrel: Maintenance of Hand Pruners

Resources

• Brooklyn Botanic Garden: Outfitting the Pruner: Tools and Equipment