The new Large Handheld Foam Herbicide Dispenser from Green Shoots will launch in March, 2014. Two nozzles will be available: the foliar nozzle works especially well for foliar applications of foam herbicide to woody plants. the extension nozzle works well for spot treatments such as cut stump treatments. Here is a You Tube video of the Large Handheld being used for a stump treatment using triclopyr herbicide (Dowagro trade name: Garlon 3A; it is also sold under the Ortho trade name Brush-B-Gon). Triclopyr is often used for woody brush. Note in the video how precise the application with no drippage and full absorption into the stump face. The extension nozzle is approximately 15 inches long so it gives you great reach. That means less bending and stooping. If you are doing more than a couple hours of stump applications, that means a lot!
Post contains content updated on August 20, 2018:
I remind people every year that late summer and fall are great times to apply herbicides to kill perennial invasive plants. I have discussed the timing of herbicide applications in several previous posts. So, get out and enjoy that cooler weather (it will come) and, for those of us farther north, beautiful fall colors!
In terms of priority, I would put perennial weeds into three groups for purposes of application timing: First are the perennials that need to be treated before a frost. Plants such as bindweed, crown vetch, and Japanese knotweed, die back after a frost. Therefore they need to be treated in late summer or early fall before a killing frost.
Second are the plants such as perennial thistles. Canada thistle is a prime target. Canada thistle can be treated a little later in the fall because it is more frost tolerant. In fact, this frost tolerance can be used to your advantage. If nearby desirable plants have died back or lost their leaves, you can apply herbicide to the thistle with less potential for damage to the desirable plants. Just make sure you apply the herbicide to foliage that is still green.
Third are the woody perennial weeds. These can be treated with cut stem or frill treatments from the fall into late winter (just do it before warm temperatures start pushing plant sugars up to the branches for leaf out). The application should be into the vascular system of the tree or shrub, e.g., cut stump, frill, or injection. The Directions for the Green Shoots Foam Herbicide System show how to do these applications.
You can also do foliar applications to woody perennials in the late summer and fall. Timing can be a little tricky: if you have had a drought, the leaves of the weed tree may be sparser and may not absorb the herbicide as well.
R&D has been ongoing at Green Shoots with our next generation foam herbicide dispensing system. Our forthcoming product will be designed for professional use. More than likely, it will have a backpack tank and a wand or lance for application of the herbicide. We will keep you posted on our progress.
John Lampe presented at the Upper Midwest Invasive Species Conference held in La Crosse, Wisconsin, from October 29-31. The presentation was entitled: “Injection of Herbicides into Rhizomes of Knotweeds and Other Invasive Species.” (View presentation.)
This was another great conference! About 400 people attended. Experts are doing all sorts of research. One very encouraging sign is that many young people are learning about invasion biology and are now conducting cutting edge research.
Green Shoots sells concentrated glyphosate in quanitites that are ideal for homeowners who are tackling woody brush or weed trees. We sell a 16 ounce bottle of concentrated glyphosate (41% active ingredient). Many stores sell what they call concentrated glyphosate. Don’t be fooled. Usually the concentration is well under 20%.
Especially if you are doing cut stump or frill treatments, a concentrate is essential. Glyphosate works well on plants in a concentrated form. It is almost like a quarterback blitz – glyphosate works better with a quick rush than with steady pressure. That’s why you need the concentrate.
Feel free to contact me with any questions. Just go to the Green Shoots website for contact info.
Fall is generally the best time to control perennial weeds. Perennials are moving sugars from above-ground sinks – in particular foliage – to underground sinks – rhizomes and roots, for example. for overwintering. In order to kill perennial weeds, these underground sinks must be destroyed.
Fall offers other benefits as well – cooler weather, less dense foliage, and fewer bugs!
What is the best way to kill invasive perennials? Several rules hold. Apply herbicide only to living tissue. Perhaps that’s obvious. That can be green leaves or stems or vascular tissue.
Since most people are probably least familiar with vascular treatment methods, I will discuss those. Photos above show each of these methods step-by-step. One method is to do a cut stump application. With this method a weed tree is cut down and herbicide is applied to the cut-surface of the stump. For most homeowners who used water-based herbicides, you should apply the herbicide soon after the cut is made. (There is debate about how soon but I try to do it within a few minutes if possible.) Two keys to this method are: first, make the cut as close to the ground as possible (e.g., 2 to 3 inches if possible); second, make sure you apply herbicide to the outer edge of the stump just inside the bark. This will ensure herbicide gets introduced into the phloem which will carry the herbicide into the root system. The Green Shoots foam herbicide system works great with this method because the foam stays on the cut-surface and doesn’t drip down the sides of the stump.
Another method is a frill application where the tree is left standing and cuts are made into the bark of the tree. Use a knife or chisel on smaller trees and a hatchet on larger trees to make the cuts. Apply herbicide to the exposed vascular tissue. These cuts should be made as close to the ground as possible. Of the two methods, I find the cut-stump method to be the most effective. However, the frill method probably takes less work especially when you are dealing with big trees.
For green-stemmed perennial weeds, I use a slightly different method. I bend the stem near the ground and apply the herbicide at the bend. For some reason, this method works better than just cutting off the stem. I don’t know why. The Green Shoots foam herbicide system works especially well with this method because the foam sticks tightly to the bend in the stem unlike methods that use liquid herbicide. This technique can be often be used even after the leaves are nipped by frost as long as the stem is still green.
For all these methods, use a concentrated herbicide mixture. For example, if I am using a glyphosate-based herbicide, I typically use a concentration of about 35 % active ingredient.
There are a number of benefits to these methods of application. First, they are very effective. I typically have a 100% kill-rate using the Green Shoots foam herbicide system with these methods. Second, they protect the environment. The methods allow for very targeted applications. And with Green Shoots foam, the herbicide sticks well to the target surface and very little drifts through the air or drips off onto other plants.
Treating a tall weed with herbicide or weed killer can be a challenge – especially if the target weed is near desirable plants. Conventional sprays are difficult to control. Fine droplets are hard to see, so it is difficult to know what you are treating with the herbicide spray. Moreover, the fine droplets in sprays have a tendency to drift. And, when the droplets do land on the target weed, they may bead and roll off the leaf.
This video shows an application to a perennial thistle using the Green Shoots Foam Herbicide System (link to video). Note how precise the herbicide application is – without drift, drip, or off-target spray. Toward the end of the video you can see the results where the weed has dead fifteen days after treatment.
These are shots from a video: Killing Invasive Bull Thistle (link).We are using the Green Shoots small foam herbicide dispenser (link) to make this precision application on a bull thistle rosette (Cirsium vulgare) . We are also using a non-selective herbicide, glyphosate, so if we had touched any grass with the foam herbicide the grass would have died too. This shows just how pinpoint these applications can be.
To view general information on bull thistle and other biennial thistles, visit this webpage from Purdue University’s Botany Department.
We just finished a video on how to control Canada thistle using the Green Shoots foam herbicide system (link). The video shows how our small foam herbicide dispenser creates a thick foam herbicide that sticks well to leaves and green stems. In the video we use the small foam herbicide dispenser and physically wipe small amounts of foam to the leaves and green stem.
We are using glyphosate herbicide with the wiping technique. The label that accompanies the herbicide you use should explain more about herbicide wiping. Many labels recommend a
33% to 100% solution for use with wiping. However, you can use a less concentrated herbicide solution than that. We are using a 10% concentration in this video.
Background on Canada Thistle – Canada thistle (Cirsium arvense) is an invasive thistle in North America and is identified as a noxious weed in many states. It is an exotic or non-native species brought to North America from Europe (not Canada!) possibly as early as the 1600s. Since that time, Canada thistle has invaded prairies and grasslands, especially in the Midwest, Great Plains, and southern Canada. It out-competes desirable, native species like grasses and wildflowers. In this way, Canada thistle degrades wildlife habitat and reduces ecological diversity.
Canada thistle has rhizomes (underground stems) that grow laterally and up to a depth of about 3.5 feet. New shoots develop from the rhizome and thus a stand of Canada thistle might orginate from one rhizome.
Other common names include: Californian thistle, Canadian thistle, creeping thistle, field thistle, corn thistle, perennial thistle, field thistle. For more information on Canada Thistle, visit the United States Department of Agriculture National Agricultural Library (link).
With wipe applications, a device is used to “physically wipe” an herbicide onto a plant. Johnson et al. 2012 (link). Because these applications are precise and controlled and generally made only to a portion of the plant, the herbicide concentration in the spray solution typically used is higher than with other foliar applications. Green et al. 2003 (link). For example, for AquaMaster (an herbicide containing glyphosate), the label recommends solutions having from 18% active ingredient to 54% active ingredient for wiper applicators.
The herbicide wiping method can be used very effectively with the foam herbicide dispenser from Green Shoots (link). The photos above show an application of foam herbicide I made with the Green Shoots Foam Herbicide Dispenser to a weed tree (maple seedling) located in a planting bed.
The herbicide solution used in this case had approximately 20% active ingredient (i.e., a low concentration for the typical wiper applications). Moreover, I applied very small amounts of herbicide foam to the leaves. Nonetheless, it appears the woody weed completely died. We will keep testing less concentrated solutions in order to minimize herbicide usage as much as possible.
Wiping with an herbicide foam has real advantages. The wiped foam herbicide is much less prone to drip. Traditional herbicide wipers work with sponges or canvas which can become saturated and drip. Moreover, clumps of herbicide foam stick better to plant surfaces than large herbicide droplets from a standard wiper system. Finally, with foam herbicide wiping, there are no sponges or canvas cloths that may become contaminated with dirt and dust or that need to be cleaned afterwards.
We will keep testing wipe application techniques on various plants and will post blog updates and videos.