The propagation of a cedar tree offers a rewarding opportunity to cultivate a landscape feature from a cutting or a small seed. The term “cedar” commonly applies to several genera of evergreen conifers, including the true cedars (Cedrus), Arborvitae (Thuja), and Junipers (Juniperus). Successful propagation requires understanding the distinct biological differences between the two main methods: asexual reproduction through cuttings and sexual reproduction through seeds. This guide details the techniques necessary for a high success rate with either approach.
Selecting the Best Cedar Species for Home Propagation
The most effective propagation method depends directly on the specific cedar species being grown. True cedars (Cedrus), such as the Atlas or Deodar Cedar, are commonly grown from seed. This sexual reproduction method is favored for Cedrus species, though it results in genetic variation and a longer timeline to maturity.
Conversely, species like Eastern Red Cedar (Juniperus virginiana) or Western Red Cedar (Thuja plicata) are frequently propagated using cuttings. This asexual method is preferred to maintain the exact characteristics of a parent plant, especially for named cultivars like ‘Green Giant’ Arborvitae. Utilizing cuttings ensures the new tree will be a genetic clone, preserving specific growth habits or foliage color.
Step-by-Step Guide to Propagating Cedar from Cuttings
Propagating from cuttings begins with selecting the right plant material, typically in late summer or early autumn. At this time, the new growth has reached the semi-hardwood stage, meaning it is firm but still somewhat flexible. Select healthy, current-season lateral shoots that are 4 to 8 inches in length.
Prepare the cutting by stripping the foliage from the lower one-third to one-half of the stem to expose the nodes, which are the sites of potential root development. Many propagators prefer a cutting that includes a small piece of the older branch, known as a “heel,” as this tissue junction encourages rooting. Dip the base of the cutting into a rooting hormone, such as Indole-3-butyric acid (IBA) at a concentration between 1,500 and 5,000 parts per million.
Plant the treated cuttings into a well-draining propagation medium, such as a mixture of peat moss and perlite or coarse sand. Insert the cuttings deep enough so that the lowest exposed nodes are fully buried beneath the surface. The rooting environment must maintain high humidity and warmth to prevent desiccation and stimulate root growth.
A clear plastic dome or bag placed over the container creates the necessary humid microclimate. Applying bottom heat, maintaining the medium temperature between 65°F and 75°F, significantly accelerates callus formation and subsequent rooting. This heat is beneficial during the first four to six weeks of the process.
Step-by-Step Guide to Propagating Cedar from Seeds
Successful cedar propagation from seed depends on mimicking the natural conditions that break the seed’s dormancy. Start by collecting mature cones in the fall, then dry them in a warm, low-humidity area to encourage the scales to open and release the seeds. Clean the extracted seeds thoroughly to remove any debris or pulp.
Cedar seeds possess a deep dormancy that must be broken through cold, moist stratification, simulating a natural winter period. Mix the cleaned seeds with a sterile, moist medium like peat moss or vermiculite, ensuring the medium is damp but not saturated. Seal this mixture in a breathable container or plastic bag and place it in a refrigerator between 33°F and 41°F.
The duration of this chilling phase varies by species, ranging from 30 days for some Thuja species to 60 days or more for Cedrus and Juniperus. Once stratification is complete, sow the seeds in a container filled with a well-draining, fine-textured growing medium. Plant the seeds shallowly, typically between 0.4 and 0.6 inches deep, and cover lightly with soil.
Keep the containers in a bright location that receives indirect sunlight and maintain consistent moisture. Avoid oversaturation, which can cause fungal disease. Germination can be erratic and may take several weeks even after stratification, but providing warmth, ideally around 70°F, encourages emergence.
Transitioning Young Cedars to the Landscape
Once cedar cuttings have developed a robust root system or seedlings have grown their first true leaves, they are ready for the next stage. This involves gradually acclimating the young plants to the outdoors through a process called hardening off. Begin by placing the containers outside in a shaded, protected location for a few hours daily, progressively increasing the duration and exposure to sun and wind over two weeks.
After hardening off, rooted cuttings and seedlings should be potted up into larger containers before final planting. Use a standard, well-draining potting mix in a container size appropriate for the plant, such as a one-gallon pot. This ensures the root system is strong enough to support the tree’s growth once transplanted permanently.
Select a permanent site with well-drained soil, as cedars are susceptible to root rot in standing water. The ideal location should provide full sun to partial shade, depending on the species’ preference. When planting, ensure the root collar—the point where the trunk meets the roots—is level with the surrounding soil to prevent future structural issues.