This YouTube video shows how to use the new Large Foam Herbicide Dispenser from Green Shoots for spot treatments of non-woody weeds like thistles. Last month we introduced a YouTube video showing how to do spot treatments of cut stumps to kill invasive trees or shrubs. In both videos, we have attached the extension nozzle. The extension nozzle enables
precision herbicide applications thereby reducing off-target harm and herbicide waste. One added benefit of the extension nozzle: the extra reach means a lot less stooping or bending. The Large Foam Herbicide Dispenser will be offered for sale starting in the Spring of 2014.
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!
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.
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.