Ulmus parvifolia, commonly known as the Chinese or lacebark elm, is a deciduous tree native to China, North Korea, Vietnam and Japan. Mature Chinese elms average about 30 to 60 feet tall, however dwarf varieties of the tree are commonly used as bonsai trees. The name "Lacebark" comes from the tree's appearance when it exfoliates its tan, red and grey bark. Chinese elms are most commonly propagated using semi-hardwood stem cuttings from a "mother" plant to create clones.
Take a semi-hardwood cutting from a healthy Chinese elm during summertime, between July and September. The sample should be about 6 inches long with fully mature foliage. The wood should be partially mature, not green, but still flexible. Sterilize a pair of sharp garden shears with rubbing alcohol or a solution of one part bleach to nine parts water. Make your cut directly below a leaf node.
Leave the sample in water while you prepare the rooting medium. Fill a 10-inch planting pot with peat moss or a mix of one part peat moss to one part vermiculite or perlite. Poke your finger into the center of the rooting medium to make a 3-inch deep hole.
Pinch off the leaves from the lower 3 inches of the cutting. Dip the cutting in rooting hormone so that the lower 3 inches is completely covered with it. Slide the sample into the hole you created earlier. Tamp the rooting medium around the cutting.
Water the pot liberally until the rooting medium is moist all the way through. Roll the sides of plastic bag down so that you can lay the bag flat. Place the pot in the bag, roll the sides up and close the top of the bag with a twist tie or rubber band. Make five to 10 slits in the bag with a razor blade or utility knife.
Put the bagged pot in a warm room in indirect sunlight. Open the bag every other day to mist the cutting with a spray bottle. Reseal the bag after watering. Repeat this process for eight to 10 weeks, which is about how long it will take for the cutting to take root. Test for roots by pulling on the cutting. If the cutting sticks to the soil, you will know that roots have formed.