How to Propagate Rosemary from a Single Sprig

Start by selecting a healthy and vigorous rosemary plant to take your cutting from. Look for a stem that’s about 6 inches long and has plenty of leaf nodes.
Using clean sharp pruning shears, take a cutting from the selected stem. You’ll want to make a clean cut just below a leaf node.
Remove the lower leaves from the cutting, leaving only a few at the top. This will help the cutting put its energy into growing roots instead of supporting foliage.
If you’re using rooting hormone, dip the cut end of the stem into the hormone, then gently tap off the excess.
Fill small pots with potting soil and water lightly to moisten the soil.
Make a small hole in the center of each pot and place the cutting in, gently pressing the soil around the stem to hold it in place.