The lace leaf maple tree or the Japanese lace leaf maple tree (Acer palmatum var. dissectum), which grows in U.S. Department of Agriculture hardiness zones 5 through 9, depending on variety, can be propagated through seed, cuttings or grafting. However, grafting has been the long preferred method for growers. Seeds do not always reproduce similar characteristics to the parent tree, and cuttings sometimes have difficulty establishing roots. Side grafting, bench grafting and bud grafting have been used successfully for the lace leaf maple.
Grafting Tools and Supplies
You will need a good grafting knife that is well sharpened. A dull knife will make the task much harder and will potentially damage the tree. You will need some grafting wax, either hand wax or brush wax. Grafting wax helps to keep the graft from drying out. Gloves may be used for applying the hand wax. The other item you will need is something to keep the scion, which is the stem or branch taken from the parent tree, and the understock, the tree receiving the graft, tightly together. Grafting tape, budding strips and nails are the three most common items for holding scions to the understock. Grafting tape is a special tape with a cloth backing that eventually decomposes. Budding strips are made of elastic and are used most often for grafts with small scions and understocks. Veneer grafts are best held in place using nails that are about a 1/2-inch long. A grafting tool may also be helpful for holding the slit open for the insertion of the scion. Remember to keep all knives and other grafting supplies out of the reach of the kids. You will need a scion that comes from the same kind of tree you will be grafting into. It should be the thickness of a pencil or 1/4 to 1/2 inches in diameter. Scions will keep up to two months wrapped in plastic in the refrigerator.
Side and Side Veneer Grafting
Like all methods of grafting, side grafting should take place after the threat of severe cold but before the heat of the summer. Side grafting involves joining the scion to the side of the understock. An understock should be at least 1 inch in diameter. To make a side graft, take a heavy knife and make a slanting cut at an angle of 20 to 30 degrees from the axis of the branch or trunk. Bend the understock back slightly to open it for receiving the scion. Insert the scion so that the cambiums come into contact with each other. Tie or nail the graft in place. Apply grafting wax either by hand or with a paintbrush or waxing brush. If the understock is less than 1 inch in diameter, the side-veneer graft is the best method for grafting. As with the side graft, a slanting cut is made in the understock. However, the cut should be no more than 1/4-inch long. A second cut is made into the bottom of the first, creating a notch section in the understock. This cut should form a 45-degree angle with the first. Cut the scion so that one side is long and sloping and the other is sharply angled. The cut in the scion should match that of the understock. The graft should then be tied or nailed and the wax applied.
Bench or whip grafting is used when both the scion and the understock are the same diameter, preferably 1/4 to 1/2 inch. Scions may be taken from stems or roots. The two are cut at the same sloping angle, 1 to 2 ½ inches long and sloped. To get an even better fit, the whip-and-tongue method may be used in which a “tongue” is cut into the slanted tips of the scion and the understock. To cut the tongue, make a ½-inch long slanted cut one-third of the way down the slanted portion of both pieces. Make sure the cuts are identical and that the edges are as smooth as possible for an easy fit. After the two pieces have been fitted together, wrap with grafting tape or budding strips and coat with grafting wax. Grafting tape and budding strips should always be removed once the scion begins to grow to prevent girdling.
Bud grafting differs from the other methods of grafting in that single buds are used as scions rather than short stems. For this method, find a year-old branch with a vegetative bud on it. Pinch off the adjoining leaf but leave the leaf's stem. Cut a horizontal nick above the bud and slice under it so that a 1 inch long wedge with a bit of sapwood is formed that can be used as the scion. On the understock, make a 1 ½ inch vertical cut through the bark. At the top of the cut, cross it with a horizontal "T" cut. Pry the edges of the bark open. Using the leaf stem as a handle, push the bud down into the T-shaped cut until it is completely enclosed in the bark. Wrap it with grafting tape. You will know the graft has taken when the leaf stem has fallen off.