My father has some kind of tropical “tree?” in a pot. It has only a few long slender leaves on top. There are two limbs (coming out of one short trunk), and the taller one is getting very tall (6 feet maybe?), and he wants to know if he can cut a section out of the middle, maybe two feet of plant, and graft the top 6 inches back on, so he doesn’t lose the leaves, but will make the plant shorter.
Thank you for your inquiry. Without a photo it is difficult to say exactly what kind of plant you have however, from your description I believe your plant to be a type of dracaena. Dracaena is a large family of plants which are often grown indoors for their attractive foliage.
There are a number of ways to propagate dracaenas. Dracaenas can be propagated by root cane cuttings, tip cuttings, and grafting. By far the easiest meth0d of propagating this plant is by tip cuttings. Below is some very in depth information, from https://homeguides.sfgate.com/dracaena-marginata-plant-propagation-31531.htm.
Tip Cuttings: This method of propagation utilizes the growing tip of the plant. The growing tip that is utilized can either be from a main shoot or a side shoot. When taking a tip cutting it is important to make sure that the tip cutting is not too long or too old. The most actively growing part of the stem is the growing tip, as a result the tip cuttings should be no more than four to six inches long. This length should include at least 2-3 nodes (point on the stem where one or more leaves are attached). Remove all but a few leaves at the top and dip the lower two inches in rooting powder which is readily available from your local garden center. Stick the cutting two inches deep in a pot of sterile potting mix or seed-starting medium. Tip cuttings need a moist environment as moisture stress may result in wilting. Enclose the pot in a plastic bag or cover it with a clear plastic soda bottle with the bottom cut out and keep it out of direct sunlight. Cuttings can be repotted once roots have formed. This type of propagation is best done during Spring to Autumn when the plant is actively growing. The plant base from which the tip cutting was removed will also begin to sprout new growth. Leave at least six inches of the cane in the pot when you remove the top part of the original plant for tip cuttings. Continue to keep the soil moist, and in a few weeks, a pair of new shoots form to take the place of the old top growth. Fertilize the plant with a balanced liquid houseplant fertilizer every two weeks after the new shoots appear.
Root Cane Cuttings: Dracaena’s foliage grows on top of long, bare stems called canes. The canes can be cut into pieces about two inches long. Each cane should posses one node ( part of the plant stem from which one or more leaves emerge). You may get faster results and stronger roots if you roll each cane piece in rooting hormone. Lay the pieces horizontally on a tray of sterile potting mix or seed-starting medium and push them down so that about half of the cutting is above the soil. Enclose the tray in a plastic bag to keep the humidity high and place it out of direct sunlight. The plants are ready for repotting once new shoots and roots begin to form.
Please refer to the following website: http://homeguides.sfgate.com/dracaena-marginata-plant-propagation-31531.html
Grafting: Grafting is the process of joining the lower part of one plant, called the rootstock, to a cutting, called a scion, from a second plant. All graftings require the cutting and trimming of stock and scion into shapes which will enable them to be neatly joined.Choose the scion that you want to graft to the rootstock. The diameter of the dracaena scion should be equal to the diameter of the rootstock, or as close to equal as you can get. Cut the scion off the “donor” dracaena using a sharp knife. Wrap the cut edge in wet paper towels.Cut a diagonal notch into the rootstock’s stem where you want the scion to grow. Make sure the cut is deep enough to expose the inner tissue (cambial layer) of the stem without cutting all the way through the stem. Leave the flap formed by the cut in place.Unwrap the scion and use the knife to cut off the bottom of the scion’s stem diagonally. Insert the cut end of the scion into the cut on the dracaena rootstock. Try to make the two cut edges fit together as closely as possible. Trim the scion stem, if needed to form a better fit. Press the flap of bark back into place to help hold the scion cutting. Wrap the graft with grafting tape and seal the grafted area with grafting wax or plastic wrap. Both products are available at most garden centers. Make sure to keep the plant evenly moist but not wet. Place the pot on a saucer filled with pebbles and water to increase the humidity around the plant this will help reduce moisture stress and wilting. Cut back on watering during the winter months and place the plant in bright, indirect light. Dracaenas tolerate some fluctuation in temperatures, but keep the plants out of drafts.
The following websites give additional information on the propagation of dracaena : https://apps.rhs.org.uk/plantselector/plant?plantid=2845
Good Luck and continue to enjoy this lovely plant.