Controling Eastern Red Cedar in CRP, Pasture or other areas.
The need to remove woody vegetation from fields enrolled in the Conservation Reserve Program (CRP) has sparked numerous questions regarding methods of controlling eastern red cedar, one of the more prevalent woody species to invade these areas.
Eastern red cedar is native to North America, and can reach heights of 50 ft. The tree is not a true cedar, but rather a juniper species. Eastern red cedar is dioecious, meaning that individual trees are either male or female. Other important dioecious weeds include Canada thistle and common waterhemp. Trees do not flower until they are about ten years old. The fruits of eastern red cedar are consumed by many bird species, providing a long distance dispersal mechanism for the seed.
Several control options are available for removing Eastern red cedar, the best choice for a situation is dependant on size of trees, characteristics of the habitat and availability of equipment.
Mechanical Red cedars can be controlled by cutting the tree below the lowest branch. When cut below any green growth the tree will not resprout, eliminating the need for cut surface herbicide treatments. Mechanical removal is probably the most appropriate strategy for many situations, and a variety of tools (brush hogs, chainsaws, etc.) are available for removal of cedars and other woody species.
Burning can effectively control small cedars. Prescribed burning of grasslands is an effective method for controlling red cedar in certain situations. The amount of fuel required to control the cedars is directly related to tree size, and large cedars may not be killed in many situations.
Chemical A few herbicides are registered for controlling Eastern red cedar in CRP and similar areas. Trees larger than two feet in height generally will be controlled better with spot treatments rather than broadcast applications. Some of the restrictions for use of these products are listed in Table 1. Carefully read the label before purchasing and using any herbicide.
Basal soil treatments Tordon 22K or Velpar can be applied undiluted directly to the soil under the dripline of trees. Tordon 22K should be applied at 3 to 4 ml per 3 ft of plant height, whereas Velpar is applied at 2 to 4 ml per inch stem diameter at chest height. Herbicides can be applied with a syringe or with specialized spot-gun applicators. Apply the chemical to several spots around the tree. Treatments should be made in the spring or fall. Tordon 22K is a Restricted Use Product.
Foliar application The effectiveness of foliar treatments for red cedar decreases rapidly with increasing tree size. For example, researchers at University of Nebraska found that 8 pt Grazon P&D provided 95% control of cedars less than 1 ft tall, whereas less than 80% control was obtained of trees between 1 and 2 ft. Products containing picloram (Tordon 22K, Grazon P&D, Surmount) have provided the most consistent control of red cedar. Tordon 22K is labeled for use as a 1% solution for spot treatment of larger trees.
Reclaiming land taken over by eastern red cedar requires considerable investment of labor and resources. Due to the relatively low economic return provided by areas red cedar typically invades, many landowners tend to ignore the cedars when they first begin to infest the field. However, the cost to control cedars increases rapidly as the trees increase in size. Thus, implementing a management program when the cedars are first spotted is the most efficient approach to managing this weed.
April 28, 2006
Prepared by: Bob Hartzler
Extension Weed Scientist
Department of Agronomy Iowa State University
Ames, IA 50011
515-294-1164
hartzler@iastate.edu
Select to see the entire article along with Table1: Chemical Restrictions List.