How To Propagate White Cedar Trees

Root stem cuttings of white cedar for faster results than growing from seed. Although not a "true cedar" in the ‌Cedrus‌ genus, white cedar (‌Thuja occidentalis‌, USDA zones 3-7) is one of the most popular evergreen shrubs available for hedging and privacy screens. It goes by many names, including American arborvitae, Eastern arborvitae, Northern white cedar or Eastern white cedar – or just "white cedar."

Thick, green foliage forms a dense, pyramidal or conical shape that reaches heights of 40 to 60 feet with a spread of 10 to 15 feet. Trees in the home landscape may not grow taller than 30 feet. White cedar grows slowly and so will your rooted cuttings, but if you follow a few simple instructions, you'll soon have healthy offspring from the mother tree.

Take cuttings from white cedar trees in the summer. Wait until the new, tender growth has hardened a bit; hardwood cuttings have the best rooting success rate. Avoid taking cuttings in the afternoon when plants may be heat-stressed; instead, take cuttings early in the morning.

Fill medium-size flowerpots with a soilless potting mixture in preparation for receiving the cuttings.

Take three to four 6-inch stem-tip cuttings from this year's growth of cedar branches with a sharp knife. Test branches with your fingers. They should be light brown instead of green, with plenty of foliage. Cut at a 45-degree angle to leave a large surface for absorbing rooting hormone and moisture. Do not cut straight across the stem.

Pinch off foliage from the bottom half of each cutting. Wrap the cuttings in wet paper towels and place them in water to keep them moist until you can root them. Don't let them stay there for more than an hour or two.

Dip the bottom 1/3 of the white cedar cuttings in rooting hormone, covering the surface completely.

Tap off excess hormone and press the cuttings in the soilless potting mix, covering the bottom half of the stem. Pat the mix firmly around the cutting with your fingers so the potting mix makes firm contact with the stem.

1. Protect the Cuttings

Put the flowerpots in clear plastic bags and seal their tops with twist ties. Poke several small holes around the top of the bags with a sharpened pencil for ventilation. Place them in a warm room with bright, indirect light but out of direct sunlight.

Open and mist the cuttings each day with a spray bottle of water. Reseal the bags to trap humidity inside. Test the cuttings after eight weeks. If they resist a light tug, rooting has occurred. Typically, it takes eight to 12 weeks for the cuttings to root.

Transplant the rooted white cedar cuttings into pots of regular potting mix after three months.

Take the potted cuttings outdoors so they can acclimate gradually. Transplant your new white cedar trees into the landscape in late fall or early spring.