How to Graft Yellow Birch Trees

Cut two 12-inch branches from the donor tree using a sharp pair of pruning shears. Choose 1-year-old wood that has at least three buds. These two branches are the scions that will attach to the understock during grafting. The donor tree must be a member of the birch tree or Betula family in order for the graft to be successful. Grafting between species usually ends in failure.

Choose a healthy piece of understock that is at least 8 inches in length from soil line to tip. The understock should be free of knots and disease. Cut the top 2 inches from the understock using the pruning shears. Understock shoots or runners are extensions of the mother tree -- in this case the yellow birch -- poking through the soil line and reaching about 12 inches into the air with a diameter similar to that of a pencil.

Create a cleft cut in the top of the understock by using a sharp knife or grafting tool. A cleft cut is a 3- to 4-inch deep horizontal cut made across the grain of the wood. The cleft helps to hold the scions in place during grafting.

Taper the cut ends of each scion using the knife or grafting tool. To make the taper, slide the tool along the side of the scion, removing about 2 inches of bark from the tip of the branch. Rotate the scion 180 degrees, and remove 2 inches of bark from the tip of the other side of the scion.

Insert the tapered end of each scion into opposite ends of the cleft cut. In other words, insert one scion into the edge of the cleft cut farthest to the right, while inserting the other to the far left.

Brush all of the cut edges that extend beyond the graft with grafting wax. This normally includes the top and sides of the cut edge of the understock as well as cut pieces of scion that rise above the cleft cut and the cleft cut.

Check the graft every few days for signs of healing and growth. Once the grafts take, remove the weakest one, which is the one that shows the fewest signs of growth, by pulling it gently from the cleft. Leave the other graft to grow intact.