Controlling eastern redcedar
By David G. Hallauer
Meadowlark District Extension Agent
I saw a graph from a 1973 article by KSU Range Professor Clenton Owensby showing the increase in redcedar at two locations. In a span of 10 years, their density went from 10 per acre to 170 per acre. Invasive would be a polite description. Think about the reduced grazing. If you figure that 100 trees with a diameter of three feet covers about 2 percent of an acre, just imagine what larger trees can do. They also use a lot of moisture (the need it all winter), further reducing forage production. Once a tree gets started and produces seed--watch out.
So we need to get rid of them, right? We typically use three different control methods (listed in order of preference): prescribed burning, mechanical control, and chemical control.
Prescribed burning is great--if you have enough fuel (we typically don't have that much forage left), trees are less than 3 to 4 feet tall (they grow 6 to 12 inches per year), and you get a fire that scorches at least two thirds to three fourths of the needles. Less, and it likely survives. This year, I'd caution against burning unless we get significant soil moisture. Trying to manage a prescribed burn with dry fuel is difficult. Further, fuel height may simply not allow it and we don't want to be burning brome/fescue very often, or too late. You'll have to evaluate in the spring to see if a prescribed burn is even an option.
Consider mechanical control, too. If cut off at ground level below the first green branch, you can kill outright--without stump treatment. Once trees reach four feet tall, it may the only control option. You may have easier access to the tree's base when combined with a burn.
Chemical control options are limited--and maybe costly. Picloram applied as a liquid directly to the soil at the base of the plant (three to four milliliters, undiluted, per three feet of plant height) is an option in April/May or September/October (apply prior to a rain if possible). Foliar sprays (1 percent solution) are possible, predominantly effective on smaller trees. Other labeled options include hexazinone (soil applied) and metsulfuron methyl (high volume foliar). Always read and follow label instructions.
Why start now? Any control program will require some management. Don't rely on a prescribed burn to take care of what is now a "small" problem. It may not even be an option without some rainfall. Adopt an integrated approach that gives you some options.