Leatherleaf mahonia shrubs produce showy golden blossoms during late winter or early spring, when most other blooming plants aren’t in flower. This plant is undemanding and easy to grow in USDA Zones 6 to 9. The easiest and most successful way to propagate it is with cuttings. Take your semi-hardwood cuttings from this year’s growth during the summer.
Select an attractive, healthy leatherleaf mahonia to take your cuttings from. Choose unblemished semi-hardwood stems after a flush of growth has matured. Shoots that snap crisply like a fresh green bean are ready to make good cuttings from. Cut a 6- to 8-inch tip.
Combine equal parts peat moss and Perlite and fill a 3-inch clay pot to about a quarter inch from the rim. Place the pot in a shallow container of water until the surface of the potting mix feels moist. Take it out of the water and allow it to drain for a couple of hours.
Trim the cutting down to about 4 to 6 inches long, and strip the leaves and buds from the bottom 2 inches. Moisten the lower inch and dip it in powdered rooting hormone. Plant half an inch deep in the prepared pot. Water just enough to uniformly moisten the soil surface. The cutting shouldn’t be allowed to dry out while it’s rooting, but neither should it ever be soaking or wet.
Place the potted cutting inside a clear plastic bag and close it up. Poke a few small holes in the plastic to permit air to circulate freely. Set the pot in a bright spot out of direct sun in a warm location. Above a hot water heater or on top of a refrigerator are ideal spots.
Check the potting mix every two or three days and water as necessary. Don’t allow the cutting to dry out. Give the stem a gentle tug upward after about two weeks and check for development of roots. When the stem resists your pull, remove the cutting and its rootball from the pot each week to monitor the rooting system.
Remove the plastic bag once you see little white root tips poking out of the soil. The cutting is becoming well established by this time. Feed it the fertilizer diluted to half strength per the manufacturer’s recommendations.
Plant the well-rooted leatherleaf cutting in all-purpose potting soil in a 1-gallon clay pot. Relocate it to a warm, brightly lit spot of your home. If temperatures remain mild, your mahonia will enjoy being placed outdoors in a shady spot for some fresh air. Continue to keep the surface of the planting mix evenly moist, but not soggy.
Bring the plant inside when frost threatens, and keep it in a warm, brightly lit room for the winter. Plant it outdoors in the spring after all danger of frost has passed.