One of the most reliable ways to propagate euonymus is through cuttings. Semi-hardwood plant cuttings are taken from the current season's growth. The season's new growth is ready for harvest in late summer, after mid-July. The stem should be of a mature size, firm and with fully-matured leaves. Avoid, if possible, using stems that have flower buds. The cutting will use its energy to produce flowers instead of roots. Never take cuttings from plants that are diseased, weak or under stress.
Cut a 4-to-6-inch piece from a lateral stem of the euonymus. Make the cut straight across, at a 90-degree angle to the growth of the stem.
Prune all of the leaves growing on the lower half of the cutting. If your euonymus has large leaves, cut them in half across the leaf. This will help the cutting retain water.
Fill a small plastic container with rooting hormone. Dip the bottom 1/2 inch of the cutting into the rooting hormone. Tap the stem cutting on the side of the container to knock away any excess powder. Throw the rooting hormone in the small container away. Do not contaminate the main container by pouring it back in.
Fill a 2-inch planting container with moistened coarse sand.
Insert the cutting into the sand so that its bottom third is submerged. Make sure that you plant the cutting right-side-up. Any buds or leaves should face upward.
Place the cutting in an indoor spot where it will receive indirect sunlight. Stand a plastic freezer bag over the container and the cutting to help keep humidity levels high. Water to keep the sand moist (not soaking) at all times. Mist the cutting with water every other day.
Transplant the cutting into a 4-to-6-inch pot, and move it into direct sunlight once it has rooted. The cutting has rooted once it resists gentle pulling on the top of the stem. Begin test pulling after one month to see if the cutting resists. Transplant the cutting to the garden bed in a few months.