Written collaboratively by Peter Schaefer and David Graper.
While eastern red cedar (Juniperus virginiana) is native to South Dakota, and has many positive qualities, it has become a problem species over large areas of the Great Plains. Even so, eastern red cedar remains one of the more important windbreak species, and is still widely planted. Several cultivars of this species are also popular ornamentals. The cones are eaten by a number of wildlife species (cedar waxwings, pheasants, turkeys, rabbits, and others), and it provides dense cover for a number of others. It has an attractive and fragrant wood used to make cedar chests, closets, animal bedding and many small novelty items. Beyond South Dakota, eastern redcedar is found throughout the eastern U.S. over a wide variety of soil and climatic conditions. In the Great Plains, it was generally restricted to ravines and other protected areas prior to European settlement. However, the significant reduction in prairie fires that followed has allowed eastern redcedar to greatly increase in numbers and land area, primarily in pasture and rangeland.
Eastern redcedar is a small to medium sized tree, generally with a single stem and dense, pyramidal crown. Its branchlets are covered with small, overlapping, scale-like leaves (about 1/16”) as well as some sharp, narrow, longer leaves (about ¼”) that stand out from the branchlet. The cones of redcedar have fleshy scales and appear berry-like (1/4”). They are greenish-blue in the summer, becoming dark blue as fall progresses, generally at least partially covered with a waxy bloom (whitish covering) throughout. However, since eastern redcedar is dioecious (trees are either female or male), not all trees will bear cones. The bark is grayish to reddish-brown and arranged in flat, interlacing, fibrous ridges, characteristic of many trees called “cedar.”
Due to widespread seed dispersal by birds and other animals, eastern redcedar can be found just about anywhere not frequented by fire or mowing. This includes fencerows, roadside ditches and disturbed sites left untended, in addition to pasture and rangeland. Eastern redcedar produces dense shade in which few plants will grow, greatly reducing pasture/rangeland productivity.
The best time to remove redcedar is before you ever see it. In other words, using grassland management that includes prescribed fire will effectively prevent redcedar establishment. The next best time is when you first begin to notice them. On areas that are actively grazed, they will be visible when they are still quite small. However, on CRP or other lands where vegetation is left to grow, redcedar may go unnoticed until it is a foot or more tall. As with all woody weeds, the larger they are, the more difficult (and expensive) they are to remove.
Prescribed fire is perhaps the most effective means of control when the trees are small (< 6’). It is consistent with natural ecosystem processes in grasslands, and generally less expensive than other control methods. While fire is often still effective with larger trees, as the trees increase in size more fuel is required to burn through the crowns and kill the trees, increasing the chances for unintended consequences.
Mechanical methods are available for removing all sizes of eastern redcedar. Hand tools, such as loppers, pruning saws and axes work well for small trees (1” diameter or less) in a fencerow or scattered over small areas. Large areas with small trees would best be treated with a heavy duty mower, such as a brush hog. As the trees increase in size it becomes necessary to use equipment designed to cut trees or pull them from the soil. A chainsaw might be appropriate for small areas with limited numbers of cedar, but it is not an efficient method to treat a large number of trees and/or larger areas. In these situations, large equipment such as bulldozers or mechanical tree harvesters (often a skidsteer with a shear or cutting attachment) is required. With all mechanical methods it is critical that the cuts are made below the lowest green branch. Eastern redcedar will not sprout from the cut stump, so additional chemical treatment is not necessary.
Several herbicides are registered for control of eastern red cedar, with Tordon and Velpar most commonly used. These are generally applied as a soil treatment, although Tordon can also be applied as a foliar spray. As with the previous methods, small trees are much more easily killed than large trees.
While eastern red cedar remains an important tree for windbreak, wildlife and ornamental plantings, it is also important to keep it in its place. Be on the lookout for this potential invasive plant and try to take steps early to remove it before it becomes a larger problem.