The Propagation of Black Walnuts Through Budding
By Sterling Smith, Ohio
The propagation of black walnuts by budding has proven a highly successful experience. By following this method over a period of several years, under normal weather conditions, the results have been fairly uniform.
Stocks, upon which to bud, may either be secured from private nurseries, state forestry departments, or by planting the seed of vigorous native nut trees. If one desires to produce his own stock, the nut seeds should be planted soon after they are gathered. A garden nursery row makes a desirable place for small plantings. If a large scale increase is contemplated it is best to plant the seeds where the trees may be left to grow to maturity. Plant two or three seeds a few inches apart (within a hill) and space these hills as the land available will warrant, anywhere from twenty-five to fifty feet apart. Should all the nuts sprout there will be a three-to-one chance for a healthy tree, and if more than one good tree is produced in each hill the excess stock may be transplanted. After the stock has grown for one year it should be cut back to within four inches from the ground. Such stock makes good material for experimental grafting. By pruning the stock in the spring it forces new growth upon which to place buds later in the season. In the budding process the Jones patch budder has been very successfully used.
Along the southern shore of Lake Erie the first week in July is a favorable time to begin this procedure. Due to the fact that the northeast side of the tree is the coolest and shadiest the greater part of the day, there the buds should be set. With the budding tool cut through the bark of the stock, several inches above the start of the new growth. Do not remove the bark. This produces a gathering of callus-forming material at this point and aids in the healing in of the bud which is to be later placed there. My experience shows successful results in many instances where I had failed to make this previous cut.
Bud wood should be new and vigorous growth, the first five or six buds nearest the spot from which the growth started being the best. When the bud wood is available cut off the first four or five leaf stalks close to the buds. By the time the buds are ready for use the remainder of the leaf stalk will have ripened or dried and fallen off, and the bark underneath hardened off. If this is not the case the bark is apt to rot at this point, which is directly beneath the bud itself. Bud wood, procured from any source, should be trimmed with the stub of the leaf stalk cut as closely as possible to the bark. If the budding is not done immediately those cuttings may be wrapped and stored in a cool place (about 40° F.) for several days before using. In a hot, dry season the actual budding should be started soon after the middle of July. Due to the excessive amount of rainfall during 1943, buds which were set on July 24th yielded poor results, while those applied later in the summer, about August 12th, healed in one hundred per cent.
Procedure: Cut the patch bud from the bud stick with the bud in the center of the patch. Place this patch bud between the lips, as this is a clean and convenient place to hold it. Next, cut the patch, which has been previously marked out, and quickly place the new patch in the opening, tying in place. As many as three or four buds may be similarly set before they are coated with wax. Parapin wax (a paraffin and pine gum mixture) is an excellent substance for coating the buds, due to its rubber-like, non-cracking qualities. A convenient homemade contrivance for melting the wax may be made by soldering a small can into the top of a railroad lantern. Rubber bands of good quality have been made especially for budding by several large rubber companies. These are ideal for tying the buds in place and may be reused several seasons. Treekote, an asphalt emulsion, has proven a successful substance for coating the new work. After the buds have set for two weeks remove the rubber bands and examine. Where buds have failed to heal in properly, and room remains on the stock, new buds may be applied just below the scar.
When the trees show signs of growth, the following spring, cut them back to the top of the bud patch, cover the cut with Treekote and prevent all growth on the original stock from developing. The placed buds are frequently slower in starting than the natural buds. A stake driven beside the young stock makes a convenient support for the rapid new growth, which should be tied to prevent breaking by strong winds.
Trees started in the nursery may be transplanted to permanent locations the following spring, inasmuch as the spring of the year has proven a more satisfactory time for transplanting than the fall. To attain success in transplanting the newly dug tree, roots should be exposed as little as possible to the air. Prepare the holes before digging the trees, moving one tree at a time for best results. Move as much of the root stock as possible, usually about 18 to 24 inches. Trim roots with a sharp knife, making a clean cut facing downward. Remove at least half of the top growth of the tree and plant at once, tamping the loose dirt firmly about the roots. Water generously and slowly around the loose soil to aid in washing the dirt thoroughly around the newly disturbed roots. With severe pruning, trees may be transplanted after new growth has started. During periods of drought the soil around the trees should be thoroughly soaked from time to time.