Tree Facts: Cedars and junipers

Farm Forum

Two of the best trees for shelterbelts in South Dakota are Eastern Red-Cedar (ERC) and Rocky Mountain Juniper (RMJ). Actually both are different species of juniper trees but both are commonly called cedars. The ERC & RMJ trees are pyramidal shaped, medium sized, slow growing, evergreen trees. Trees are either male with yellow-brown flowers or female with green flowers that form blue berries. Unlike RMJ the needles of ERC have a tendency to turn reddish brown during the winter.

RMJ & ERC are native trees of North America. RMJ ranges from southwestern Canada, locally throughout western United States in the Rocky Mountains and east to the Great Plains. Its growth form is dense, mature height from 20 to 40 feet and width from 12 to 20 feet. ERC ranges from southeastern Canada to the Gulf of Mexico and west to the Great Plains. Its growth form is less dense, mature height from 30 to 45 feet and width from 15 to 30 feet. ERC & RMJ have been known to naturally hybridize where the two native ranges meet.

In the early days of conservation districts after WWII, very few ERC & RMJ were planted in shelterbelts, but as time went on into the 1970s, their good qualities were learned and both have been planted more frequently ever since. ERC is considered to be drought tolerant and RMJ is extremely drought tolerant. Generally it is best to plant ERC in the eastern and the RMJ in the western parts of South Dakota. However, practical experience of the conservation districts in northwestern part of the state has shown that RMJ has better survival rates and does better overall in Harding, Perkins and Meade Counties and RMJ & ERC have comparable survival rates and do equally well overall in Corson, Dewey and Ziebach Counties.

Shelterbelts are planted to reduce the force of winds and direct the movement of snow. The densities of the species planted vary greatly and are directly related to how much wind is stopped and how heavy snowfalls are managed. Shelterbelt rows are numbered 1, 2, 3, 4, 5 and so on from either the west or north. Conservationists strive to design shelterbelts that provide excellent protection for farmsteads and livestock areas but there is no boiler plate recipe for which species are best for each row. Generally it is best to plant RMJ & ERC in the leeward rows 4 or 5 next to either the livestock or the farmstead areas to be protected. However, when designing shelterbelts for the long-term it is desirable to plant RMJ & ERC in the windward rows 1 or 2 and leeward rows and to plant snow load resistant species in the middle rows. Otherwise, if species susceptible to snow load were planted in the middle rows they would become crushed, deformed and possibly killed.

Besides shelterbelts, RMJ & ERC trees have many uses. Their wood is used for fence posts, cedar chests and pencils. The berries are used for flavoring alcohol products. Medicinally products are extracted and used for cancer treatment, coughs, colds, sore throats, diarrhea, bleeding, pneumonia, stomach aches, arthritis and antibiotics. Both species provide food for birds and mammals, nesting and winter cover for a variety of birds and browse for deer. They are also used for ornamental landscaping. Historically American Indians used poles from both species to mark out tribal hunting territories and needles were used as a spiritually purifying herb in ceremonies and prayer.

ERC & RMJ are tough native species but they do have some problems, especially when they are in a weakened condition from extended droughts. Common diseases include cedar apple rust, Kabatina, Cerospora, Phomopsis and Juniper blights. Common insect pests include spider mites, spittle bugs and Fletcher scale. Losses from these maladies are slight and even if dieback happens, regrowth usually occurs from the main trunk or the base of the tree.

My sources for this news release were the North Dakota State University, USDA Forest Service, USDA Natural Resources Conservation Service and Wikipedia. If you would like more information about “Cedars and Junipers,” contact Bob Drown @605-244-5222 Extension 109 or by e-mail at