EXTENSION 
INSTITUTE OF AGRICULTURE AND NATURAL RESOURCES         
UNIVERSITY OF NEBRASKA-LINCOLN 
NORTHEAST RESEARCH & EXTENSION CENTER       
601 EAST BENJAMIN AVENUE, SUITE 104
NORFOLK, NE 68701-0812
PHONE: (402) 370-4000 
FAX (402) 370-4010

Integrated Management of Eastern Red Cedar in Grasslands of Nebraska

Introduction - Eastern red cedar is a problem on grasslands primarily because it reduces forage production and livestock handling. Developing trees alter the microclimate, which encourages a shift from desirable warm-season native grasses to introduced cool-season grasses such as Kentucky bluegrass. Heavy infestations make livestock handling more difficult. All these adverse effects can be reflected in lower rental rates or sale prices for infested grassland. Established infestations usually get worse over time due to overproduction of seeds and established trees get larger, thus shading the grass beneath even more. On many sites complete coverage by eastern red cedar can be expected, resulting in total loss of grass production unless controlled. Control measures should be initiated as soon as possible, both to improve effectiveness and reduce total control costs.

Eastern red cedar ( Juniperus virginiana L.) is one of 13 juniper species native to the United States . It is the most widespread tree-sized conifer and is native to every state east of the 100th meridian. Throughout this vast range, eastern red cedar grows on many soils and under varying climatic conditions. This adaptability has enhanced eastern red cedar's recent spread into areas where it was formerly rare or absent.

Integrated management of eastern red cedar on pasture and grassland should be based on a combination of cultural, mechanical, biological, and chemical tools to keep this invasive tree under control and protect grass land production and profits. We recommend using tree-height as a determining factor for control options. Burning, cutting, digging, mowing, use of goats and broadcast herbicide application is effective on trees up to 2 ft tall. Cutting and individual-tree herbicide treatments work well on 2-10 ft tall red cedar. Trees that are over 10 ft in height are most effectively and economically controlled by cutting. The bottom line is “control trees while they are small”.

Integrated Management for Eastern Red Cedar - Integrated management has been commonly described as a multi-disciplinary approach utilizing the application of numerous alternative control measures”. In practical terms, it means developing a management program based on a best method, or a combination of methods for the particular site, which could include mechanical, biological and chemical practices.

Nebraska's eastern red cedar infestations have developed over several decades. Likewise, management of these infestations is best viewed as a long-term or on-going effort, both to reduce the initial infestations and prevent them from redeveloping to economically damaging levels. It is best to begin treatment as soon as possible. Once treatment has begun considerable time is gained to continue long-term management. The emphasis should be on management of the infestation, rather than eradication. Eradication is not economical, and probably not physically possible in most cases. Instead, it should be recognized that some remaining larger trees, which are the most difficult and expensive to kill, do little damage. In fact, at low levels, eastern red cedars can be viewed as a potential resource, providing livestock shelter, wildlife habitat, timber products, and aesthetic values. Most important, long-term selective management is considerably less expensive than a more intensive, short-term approach.

If the goal is to just reduce overall number of trees, and stop further spreading (eg. management of wildlife habitat), it is recommended to cut female trees only. Female trees are the ones that produce berry-like fruits. This would allow “male trees” to grow and provide much needed cover for wildlife, or land beautification, while reducing further spreading.

Manual and Mechanical Control - Manual and mechanical control involves methods such as digging trees, cutting and mowing. It is very effective for small areas, and it is most efficient on trees up to 2 feet tall.

Cutting is an effective method of control because eastern red cedar does not sprout. Trees cut below the lowest branches will not re-grow. A variety of handheld or motor-powered cutting tools can be used. Hand-held tools (shears, saws, spade, shovel, heavier hoe) are effective on small trees (< 5ft tall), while larger trees require a chain saw or vehicle-mounted shears. The equipment varies from tractor pulled PTO driven shredders to hydraulic drive devices that mount on skid steer loaders. Most of the shredders can easily handle up to 3-4 inch stem diameter trees, while some can cut trees up to 15 inches. In general, cutting is a method that can be time consuming and labor intensive. Cutting alone also fails to remove the problem because fallen trees continue to occupy space. Thus, all cut trees should be gathered and burned, or permanently removed from the grassland. Mowing of short trees (< 3ft tall) can be conducted using a shielded mower shortly after regular cutting and haying.

Biological control of eastern redcedar - Biological control is the use of natural enemies to reduce weed populations to economically acceptable levels. In the case of red cedar control, goats can be utilized as an effective bio-control agent for trees that are up to 3-4 ft tall. Experience from Nebraska suggests that most cedar trees < 24 inches tall were killed by goats utilizing paddock grazing system. The control level was reduced by 50 percent on 4-8 feet tall trees, however, the goats managed to defoliate bottom branches and strip bark from branches and trunks up to three inches in diameter. Many ranchers in other parts of the US have run cattle and goats together for decades. They view goats both as a profitable part of their business and as a very important part of their grazing land management program.

The grazing strategy with the goats should vary depending on the management goals set for the pasture. Adding one or two goats per cow and letting the goats and cattle run together is an excellent maintenance strategy for pasture with moderate to low cedar infestation. However, if the goal is to get a quicker response and try to suppress denser stands then the area needs to be fenced off using temporary fencing. Thus per acre stocking rate should be at least 10 goats/acre of land infested. This stocking rate with moderate cedar infestation should result in significant damage to the trees within 30 days. Higher stocking rates would be better, but will require moving the fence more often. Trees and other perennial plants have high energy reserves in their root systems and repeated defoliation over a few years is required to control them. Cedar trees however, will not re-sprout and thus, if the goats remove most of the needles and/or bark, the tree will eventually die. Other issues that need to be addressed before getting goats may include predator control (eg. coyotes) and perhaps learning how to raise goats for meat production. A good place to start is at the ATTRA - National Sustainable Agriculture Information Service web site. The page “Goats: Sustainable Production Overview, Livestock Production Guide” http://www.attra.org/attra-pub/goatoverview.html has information on numerous topics relating to meat goat production.

Use of prescribed fire for red cedar control - This method is inexpensive and very effective against smaller trees. Its effectiveness declines as tree size increases, however there were cases of successful burning of tall trees. Adequate fine fuel (usually, last year's dead grass) is necessary for satisfactory results. Safety also is a concern since many managers lack experience with fire and the equipment required to conduct fires.

The controlled use of fire is a large subject in itself. It is beyond the scope of this publication to provide detailed instruction on conducting prescribed fires. Two other Nebraska Extension publications provide information on the use of fire in general and on how to safely conduct fires. They are NebGuide G88-894, Grassland Management with Prescribed Burning; and Extension Circular 90-121, Conducting a Prescribed Burn. A fire plan should be prepared and a prescribed-burning permit obtained from the local fire jurisdiction, as required by state law. Specialized fire equipment can be purchased. Two sources are the Ben Meadows Company, 3589 Broad St. , Chamblee , GA 30341 ; and Forestry Suppliers, Inc, Box 8397 , Jackson , MS 39284-8397 .

Chemical control of eastern red cedar - Herbicides can also be considered for control of this tree species, however, they should be viewed as just another tool in the integrated management program. Depending on the application method and chemical type, the use of herbicides can be time consuming and expensive, especially when used on denser tree infestations or large tracts of land. Effectiveness also is variable depending on the tree size and label directions and/or restrictions. Therefore, always read and follow herbicide label directions. Herbicide information on control of troublesome plant species, including eastern cedar, is update annually in the Guide for Weed Management in Nebraska (EC-130) In general, herbicides for eastern redcedar control can be used for broadcast application or individual-tree spraying.

Broadcast treatments - Broadcast application is the most common method of applying herbicides in agricultural settings. The key message for the efficacy of broadcast treatments in eastern redcedar control is: “the shorter the tree the better control”.

Since tree height was the most important factor influencing the level of chemical control (tree injury) with broadcast treatments, the herbicide efficacy data from Nebraska study was categorized by tree height (Table 1). Recommended herbicides for trees that are up to two feet tall include: Surmount, Grazon P&D and Tordon (Table 1). However, the same herbicides will not provide satisfactory control of trees taller than 2 ft, indicating the importance of tree heigh. Surmount at the rate of 5pts/acre can also cause short-term grass injury in the form of leaf yellowing and top growth burning (Table 1). Cost of Grazon P+D and Tordon 22 K for broadcast applications can range from $21-$26 per acre. Since Surmount is not marketed product yet, its costs is not known.

Individual-tree treatments - Individual-tree treatments can be applied directly to the tree foliage or to the soil around tree base. Soil treatments can minimize the amount of herbicide used and the exposure to non-target species. However, soil treatments may not be effective unless applied before rainfall, preferably in Spring or Fall. Rain water is needed to move the herbicide into the root zone allowing an easier uptake by a tree. Recommended herbicides for soil application around tree base include Tordon 22K at the rate of 1 cc (ml) per every foot of tree height, Velpar-L at 4 (cc) ml and Spike 20P at 1cc (ml) per every inch of tree diameter. Cost of Tordon is about $85 per gallon, Velpar is about $65 per gallon and Spike 20P is about $9 per pound of product.

Individual-tree foliage can be also treated with various herbicides (Figure 8). Based on a study conducted in northeast Nebraska, recommended herbicides for control of 2-10 feet tall trees include Surmount at 1.5 % volume per volume (v/v), Grazon P+D at 2.0% (v/v) and Tordon 22K at 1.0% v/v (Table 2).

To help you determine volume per volume basis, for example, the 1% v/v equals 1 gallon of product per 100 gallon of water. For smaller back pack sprayers use an equivalent of 1.3 oz of product per every gallon of water. Apply about 1.5 oz of the herbicide spray solution per every foot of tree height. Walk around the tree and just spray enough solution just to get a glisten (shine) on the canopy surface. Solution dripping off the canopy indicates a rate that is too high, and a likely waste of time and money. As an example, it was calculated that 1 gallon of spray solution could cover 15 individual trees that are 6 feet tall at a pressure of 20 PSI and a single nozzle type XR8002.

Grass injury in the form of temporary yellowing and burning of top growth was evident among all treatments especially for Tordon 22K. Roundup is not recommended for use in pasture settings due to poor activity on cedar trees and high injury level to the grass (Table 2). Cost of Grazon P+D and Tordon 22 K can range from $11-$16 per acre.

Practical hint for chemical control - Use of selective herbicide treatments should be based on a tree height. Broadcast treatments are effective only on short trees (up to 2 ft tall), while the medium height trees (2 to 10 ft) can be controlled with individual-tree treatments. For broadcast treatments use 6-8 pints of Grazon P&D or 4-5 pts of Surmount in a 20 gallon of water per acre. To prepare 1 gall of spray solution for individual-tree canopy treatments use 1.3 oz of Tordon, or 2.6 oz of Grazon P&D, or 2 oz of Surmount. For larger spray tanks adjust herbicide rates accordingly.

Table 1. Percent eastern redcedar control and grass injury levels at about 100 days after treatment as influenced by the tree height (feet) where herbicide treatments were broadcast applied.
	Dose	Tree Height (ft)
Treatments*	pt/acre	0 to 1	1 to 2	2 to 4	4 to 6	Grass Injury
1. Surmount	4	84	70	52	12	35
2. Surmount	5	95	81	46	20	55
3. Grazon P & D	6	90	59	51	16	15
4. Grazon P & D	8	95	79	60	18	20
5. Tordon 22K	2	85	65	33	25	20
* Treatments 1, and 2, were mixtures of picloram + fluroxypyr each at 0.66 lbs ae/gal, - Treatments 3 and 4 were picloram at 0.54 lbs ae/gal + 2,4-D at 2.0 lbs ae/gal, - Treatment 5 was picloram at 2.0 lbs ae/gal.

 

Table 2. Percent of eastern redcedar and grass injury at 100 days after treatment that were applied to individual-trees.
Treatments*	Dose (v/v)**	Tree Injury	Grass Injury
	(%)	(%)	(%)
1. Surmount	1.0	75	39
2. Surmount	1.5	89	48
3. Grazon P & D	2.0	9	50
4. Tordon 22	1.0	94	60
5. Roundup Ultra	1.0	5	55
6. Roundup Ultra	2.0	31	91
* Treatments 1, and 2, were mixtures of picloram + fluroxypyr each at 0.66 lbs ae/gal, - Treatment 3 was picloram at 0.54 lbs ae/gal + 2,4-D at 2.0 lbs ae/gal, - Treatment 4 was picloram at 2.0 lbs ae/gal. - Treatment 5 and 6 were glyphosate at 3.7 ae/gal ** Dose was a herbicide/water solution on a volume/volume basis