The Leyland cypress is a group of sterile hybrid trees. This means there are no naturally created Leyland cypress trees. A rooted cutting must be created in order to propagate. The Leyland cypress is a semi-hard to hardwood variety of evergreen plant. Take cuttings for propagation in late fall after the last growth. The tree might be in a dormant stage at this time. The Leyland cypress grows in most climates as there is no historic natural range for the tree.
Leyland Cypress Propagation
Disinfect pruning sheers or a sharp knife and workspace with rubbing alcohol or a solution of nine parts water and one part bleach prior to use.
Cut a 6- to 8-inch cuttings from th current season or from 10year-old growth on the Leyland cypress tree. Choose cuttings that are growing upright and have stems that are slightly hardened with green foliage.
Remove the leaves from the bottom 3 to 4 inches of stem.
Make an angled notch with a sharp knife in the bottom of each stem to open the structure and allow water and nutrients to move up the cutting.
Prepare a propagation medium by filling a sterile pot or jar with course sand or a mixture of one part peat and one part sand. When purchasing the medium, make sure it is labeled as "sterile."
Water the medium to make it moist but not wet. The medium must stay moist during rooting to provide the proper environment for root growth.
Dip the bare stem bottom into rooting compound to stimulate root growth. Tap any excess compound from the stem. Pour a small amount of rooting compound in a sterile dish prior to use as this prevents contaminating the entire container if a disease exists. Discard the remaining rooting compound.
Insert the stem end of the cutting at least a third the total length into the prepared medium. Make sure the stems are standing upright and not at a slant. Cover the container and cuttings with plastic to create a greenhouse effect. Place in a window or under grow lights.
Plant rooted cypress stems in potting soil once roots have set in. Rooting might take six to eight weeks.