For good grafting results, a sharp knife is an essential tool. Grafting knives differ from other knives. They have thin, sharp razor-like blades that are beveled on only one side. This allows the knife to cut through tough, woody material easily with a flat cut that provides the highest level of contact in the finished graft. For those who do a lot of propagation work, a quality grafting knife, while not cheap, is a very worthwhile tool.
Hold a grafting knife lightly in your hand. Rest your thumb along the back of the knife where the handle meets the blade to provide greater control. Grip the knife only as firmly as the job requires. For cuts across small branches, cut in the center of the blade. For larger cuts, move the branch closer to the handle for better leverage.
Cut scions from plants using a single stroke through the selected branch. Trim scion tips for fitting into cleft grafts by holding the scion with the cut tip away, and trim the tip on either side to form a wedge shape.
Cleave branches or trunks for cleft or whip grafts by carefully forcing the edge of the blade into the center of the cut end of the branch. Twist the handle of the knife to lever the split open. For larger-diameter branches, use a small wooden or plastic mallet to carefully drive the blade edge into the wood.
Make incisions in branch or trunk bark for receiving scions when you are doing budding. Use the dull back of the knife point to lift the bark away from the underlying pith wood. Remove buds from budsticks by slicing quickly and cleanly under the bud, starting about 1/2 inch below the bud and finishing 1/2 inch above it.
Girdle branches for air layering by placing the edge of the grafting knife across the branch and rolling the knife around the branch to score a ring around the bark down to the pith wood in two places. Then make an incision from one ring to the other and use the tip of the knife to lift and peel the bark away.
Trim leaves, flowers and buds by slicing them off with short forward strokes. Cut large leaves to be left on cuttings by placing the leaf on a wooden surface and stroking the knife across the leaf.
Keep an edge on the blade of the knife using a sharpening stone. Clean the blade and sharpen it after each use. Oil the blade regularly to prevent corrosion.