Propagation of Siberian Cypress & Russian Arborvitae

Propagation Technique

• Siberian cypress or Russian arborvitae is best propagated by a tip cutting. A tip cutting comes from the terminal end of a branch, meaning the growing end of the main stem. Cuttings are most effective when taken from a young, healthy plant -- around 1 year old -- and in midsummer when the new, green growth has started to darken in color and the stem to harden, according to Washington State University Extension. This state is called "semi-hardwood."

Taking and Preparing the Cutting

• Cuttings should be 4 to 10 inches long -- gauge your length to the size of the plant you are cutting from. Use clean secateurs, sterilized in a 10-percent bleach solution or rubbing alcohol, to make the cut. Cuttings taken in the morning when the plant is flush with water get a head start on the rooting process, according to WSU Extension. Siberian cypress have relatively fine stems, but if your cutting is more than a 1/4 inch in diameter at its base, gently peel back the bark in two narrow, inch-long strips up from the cut end to reveal the green cambium layer of growing cells and make a vertical slice 1-inch deep in the end of the cutting to open up the area exposed for rooting. Dip the cut end in plant rooting hormone powder to give it an additional jump start.

Waiting Game

• The cuttings should be set upright in pots or a deep tray of loose, well-draining soil-less rooting medium, like vermiculite, perlite, sand or a mix of all three. Keep the rooting medium moist and enclose the pot or tray in plastic or other covering -- a cloche for one pot or a cold frame for multiples. Maintaining moisture and humidity around the cutting until it roots is key. The cuttings also benefit from indirect light and temperatures between 60 and 70 degrees Fahrenheit. Evergreens can be persnickety, taking one to three months to put down roots, though Microbiota decussata roots fairly quickly, according to Floridata, an online plant resource. When tugging on the cutting yields some resistance, you can begin transitioning the plant to the outdoors for planting.

Considerations

• While Russian arborvitae has a wide spread, it is a slow-growing plant that can take several seasons to reach its full potential. When planting as a ground cover, you may want to plant them closer than 6 feet apart, so take multiple cuttings. Ohio State University Extension also notes that while some growers tout the performance of the plant in full shade, it grows best in full sun and only partial shade. The plant also comes in several cultivars designed to meet specific needs -- which propagate true from stem cuttings. These include Microbiota decussata "Northern Pride," which grows 5 feet tall and 3 feet wide, and Microbiota decussata "Fuzzball," which has slightly fluffy foliage and a more upright shape, growing 1 to 2 feet tall and 3 feet wide.