By: Steve Hoel, Private Land Conservationist, Missouri Department of Conservation
Disclaimer: I am not an expert in all herbicides. Always read and follow the safety and application guidelines from the herbicide manufacturer.
It’s the time of year that many of us grab the chainsaw and set off to complete some winter habitat work. On my property, winter chainsaw work includes killing trees that have begun to invade grassland areas. Along with the saw and personal protective equipment, I always take along a herbicide to prevent re-sprouting. One day, I followed my own advice and decided to fully read the herbicide label. To my surprise, according to the label, I was using the wrong herbicide for the species I wanted to kill.
It seems like the go-to cut stump herbicide is Tordon® RTU (5.4% Picloram and 20.9% 2,4-d). It comes in a convenient ready to use (RTU) formulation in a handy one quart bottle with an applicator tip. Pathway® is the same chemical combination as Tordon® RTU, but comes in a 2.5 gallon container. If you don’t mind refilling applicators, you can save a few dollars by buying Pathway®. Tordon® RTU and Pathway® should be applied to the outer cambium layer of the freshly cut stump to prevent re-sprouting.
Tordon® RTU/Pathway® are labeled to control the 21 species listed in the box below. Take note that two of the most common problem trees, Osage orange and honey locust, are not listed. I’m not saying that Tordon® RTU has not been used to kill these species, but it’s not labeled by the manufacturer to do the job.
Woody Plants Controlled by Tordon® RTU/Pathway®
I have a real problem with invading Osage orange and honey locust, so I began to search herbicide labels to find a product that was tested to control both species. In addition, I wanted to find a versatile, inexpensive, and readily available herbicide that I could purchase without a pesticide applicator’s license. After considering all of the variables for my situation, I settled on Remedy® Ultra herbicide (60.45% Triclopyr). According to the label, Remedy® Ultra controls Osage orange, locust, and the other species listed in the chart below.
Woody Plants Controlled by Remedy® Ultra
(1) Basal or dormant stem applications only.
(2) Basal or cut stump applications only.
For cut-stump use, Remedy® Ultra needs to be mixed with a commercial basal oil or other oil-based carrier, such as diesel fuel, fuel oil, or kerosene. After mixing, the product should be applied to the outer cambium as well as the exposed stump and root collar area. This effort requires a bit more herbicide than using a product like Tordon® RTU, but it can be quickly accomplished using a pressurized hand sprayer like this one-liter hand sprayer made by Solo. Note that the basal oil or oil-based carriers can be hard on a sprayer’s seals and O-rings. Be sure to select a sprayer that can handle these products.
When mixed according to the label directions for cut-stump use, the final product will include around 15% of the active ingredient, Triclopyr. Conveniently, this same mixture can also be used for a basal bark application. This is a way to control small (<6″ diameter) individual woody plants by applying herbicide to the circumference of the lower 12-15″ of outer bark and root collar. This method is great for killing small individual woody plants without using a chainsaw.
If mixing herbicide is not your thing, you can use an herbicide called Pathfinder® II (13.6% Triclopyr). It is a ready to use product that is premixed with a basal oil. It is designed for both cut-stump and basal bark applications, just like the Remedy® Ultra mix above. One difference is that Pathfinder® II is actually labeled to control more species than Remedy® Ultra (see below).
Woody Plants Controlled by Pathfinder® II
(1) Some re-sprouting may occur.
(2) Not recommended for streamline basal treatment.
(3) Suppression only with streamline basal bark treatment.
One additional feature of Remedy® Ultra is the fact that I can use it in two other ways during the growing season. When mixed with water according to the label directions,itcan control woody plants with a foliar (leaf surface) herbicide application. I also use it to control sericea lespedeza and other broadleaf plants.
This brief article can only scratch the surface on herbicide selection and use. Each person’s situation is different, so you should consult your chemical supplier and the herbicide labels to select the correct product. I am not promoting one herbicide over another, but only describing my personal experience in selecting and using herbicides for my situation. You may find similar herbicides that will better suit your personal situation. No matter what herbicide you use, I encourage you to carefully read and follow herbicide labels. CDMS’ Agro-chemical Database makes it easy to locate just about any herbicide label.
This article was syndicated from MOre Quail Blog Updates.