UT Gardens’ January 2022 Plant of the Month
Submitted by Andy Pulte, UT Department of Plant Sciences, and director, UT Gardens, GATOP
Perhaps one of the most graceful of all evergreens we can grow, deodar cedar (Cedrus deodara) can be a unique addition to your garden. This is one of the four known true cedars and can be a striking specimen. In the Southeast we are not able to provide it with ideal growing conditions. However, it’s important with this species to think through the conditions we can provide. With a little bit of forethought and perhaps a little luck, you can be successful.
Deodar cedar’s native range is the cool moist slopes of the Western Himalayas, Afghanistan and northern Pakistan. This region is one of the world’s most important biodiversity hotspots and includes more than 140 different species of conifer including C. deodara. It also includes the highest topographical regions of the world. In its native range, the tree finds extensive use among locals for thatching and shelter constructions. It is also used in various forms for medicinal purposes. In modern medicine, the anti-inflammatory activity of the essential oils derived from its wood is being studied.
Large and impressive examples of deodar cedar can be seen in the Pacific Northwest, some reaching over 100-feet in height. However, the stressful heat and humidity of the Southeast tends to keep trees slightly more petite. In our region, you can expect to see grand old trees 60-feet high and wide.
This is a pyramidal conifer with a strong central leader. Trees remain pyramidal until very old, when they can become more rounded or flat-topped. Branches spread horizontally with needles weeping towards the tips. Many cultivars are available. You can find selections with green, gold, blue or even whitish-colored needles. There are columnar cultivars as well as those known to be dwarf compared to the straight species. Homeowners will want to thoroughly investigate their different options and choose a selection that fits their needs.
One great application for this plant is as a background or garden screen. The best living screens contain a diversity of plant materials. Deodar’s unique texture blends well with other conifers. The tree doesn’t grow as quickly as traditional screening plants like arborvitae, yet it can be sturdier over time.
One key to success in growing deodar in the Southeast is good drainage. This plant does not like wet feet. Planting trees slightly above grade and making sure the root-flair (broadening of the trunk just above the soil line) is exposed when planting is crucial. Additionally, not letting trees suffer from drought stress in the hottest part of the summer is important. After two or three years of establishment, trees become less finicky and less susceptible to drought stress.
Deodar cedar has narrow climactic adaptability. You will see references list USDA hardiness zones of (6b)7-9 for this plant. However, there is a big difference between surviving and thriving, and this plant will struggle in the hottest parts of the Southeast. Even within its hardiness zones, young trees are prone to injury from frosts and cold wind. Don’t let that warning dissuade you from growing deodar cedar, particularly gardeners who have the room to grow trees to their full-size potential. You can find various selections of C. deodara in all locations of the UT Gardens.
The UT Gardens includes plant collections located in Knoxville, Crossville and Jackson. Designated as the official botanical garden for the State of Tennessee, the collections are part of the UT Institute of Agriculture. The Gardens’ mission is to foster appreciation, education and stewardship of plants through garden displays, educational programs and research trials. The Gardens are open during all seasons and free to the public. For more information, see the Gardens website: utia.tennessee.edu/state-botanical-garden.