Plum trees, like many types of fruit trees, can be grown by seed or cutting. When grown from a seed, these trees can take years to produce edible fruit. However, if grown from the cutting of a mature tree, fruit will develop a lot sooner. Rooting plum trees takes a bit of patience while you wait for roots to develop, but is well worth the end result.
Trim off a 5- or 6-inch section of a limb from a plum tree. Make sure the cut section is newer growth that is not completely hard yet. You will get the best results from a part of the tree that has recently grown in the past year. Fall is a good time to take cuttings; there are no leaves on the limb, but the tree growth has not gone dormant yet and the tree limb is able to concentrate on rooting without diverting energy to feeding the leaves.
Make the cut at a notch in the limb where a leaf is forming or where the limb is growing out from another.
Dip the cut end of the limb in rooting hormone. This will encourage growth at the cut.
Prepare a 4-inch pot with a mix of peat and perlite so that the cutting will have a good growing medium. Slide the cutting into the pot an inch or so and pack the medium around it. Water the soil to dampen, but do not make it too wet.
Cover the cutting and pot with a bottle or plastic bag to create a mini greenhouse effect. If using a bottle, cut the bottom off of a 2-liter plastic bottle, and slip the top portion of the container over the pot and cutting. You can use a plastic bag in the same manner by slipping the bag over the pot.