Spring and fall are excellent times to attack non-native thistles such as Canada thistle (Cirsium arvense). Here’s a photo of a very young Canada thistle rosette taken in early spring in a small prairie area that we are restoring.
I used our Large Foam Herbicide Dispenser with the mesh brush attachment to wipe foam herbicide on the rosettes. One nice thing about early spring is that the plants are well spaced and you can easily isolate the target weed. Thus, you can avoid harming desirable native plants.
As shown below, you can get a perfectly targeted application of the foam weed killer by wiping the foam directly onto the leaves of the thistle.
In terms of herbicide rates, most labels for glyphosate suggest rates that are pretty high for wiping. In some cases, the recommended wiping solution may have 20% active ingredient. In my opinion, this is too high. (That high rate may be suggested because conventional wiping applications with sponges or fabric wipers result in a lot of drippage.) Foam herbicide reduces the drippage to a minimum. Using foam herbicide, I have had success with rates that are about 4% to 8% active ingredient.
In terms of timing, in the spring make sure you treat the Canada thistle in the rosette stage before it starts to bolt. Once it is bolting, it will be hard to control with herbicide. In the fall, wait until you have had a frost or the weather has become pretty cold in your area. As long as the thistle leaves remain green, you can treat them.
In this piece we identify the key advantages of our new ultra-low pressure electric dispenser (patents pending). (See also this YouTube video: Electronic Dispenser Dispenses Herbicide with High Precision.)
First, when used as a sprayer (i.e., for spraying liquid drops), ultra-low pressure (i.e., less than about 15 psi) offers key benefits. The biggest is less off-target spray. We did indoor testing in 2016, where we sprayed colored water on white paper using a Hypro(R) 30HCX8 hollow cone nozzle. We sprayed at a variety of psi’s. What was particularly striking in these tests was how far the spray extended beyond the primary spray band at higher pressures. At 30 psi, the spray band extended at least 30 inches beyond the center-line! This was an indoor test with no wind. At 9 psi the “shadow spray band” only extend 15 inches. This means, if you are spraying at a high psi, you are doing off-target damage to desirable plants and wasting a lot of expensive herbicide.
Second, ultra-low pressure places far lower demands on the pump and battery. This means our electric sprayer can be far lighter than the competition. Other electric systems typically weigh well over 15 lbs. Ours, even with the fully padded backpack frame, weighs about 10 lbs.!
Third, ultra-low pressure makes great foam! For example, you can hook up our foam-making attachments with the mesh brush. Use it to wipe foam herbicide onto foliage or onto stumps. As shown below, you will get high precision, no drippage (like you do with conventional wiping systems), and extended absorption of the herbicide into the weed’s vascular system because the foam keeps the herbicide in liquid form longer. (Here’s a YouTube video: Cut Stump Treatments)
We will be producing a limited quantity of our Ultra-Low Pressure Electric Dispenser in the first year (2017). We are primarily selling it to professionals with a strong need for the benefits offered by the system. Please contact Green Shoots for availability and pricing!
Our new dispenser works great for doing basal bark applications of herbicide.
Basal bark treatments involve the application of an ester herbicide in an oil carrier to the bark of a tree. We actually dial the pressure in at 2 psi – i.e., very low! This produces a narrow stream of herbicide that can be precisely applied even to very small stems such as the one shown below. This reduces off-target harm and reduces herbicide waste. We posted a YouTube video that goes into greater depth.
Green Shoots will be offering a new electric sprayer in 2017. The sprayer will operate on ultra low pressure. This has lots of advantages including more precision and less off-target spray. This is especially important when spraying herbicides because off-target spray can harm desirable plants and waste expensive herbicides. The battery will last for a full day. The sprayer can also easily be converted into a foam dispenser. The sprayer will have all sorts of other great features, many of which are shown in the following photos.
The pressure can be adjusted in increments of 0.2 psi and from 1.5 psi to 12 psi. Pressure from about 1.5 psi to 10 psi works great for dispensing foam. Pressure from about 5 psi to 13 psi works great for spray. Green Shoots will also offer a very comfortable backpack frame with a hip belt.
Remember with this electric sprayer there is no pump lever, so one hand can hold the spray wand and the other can be free. Elimination of the pump lever also makes it much easier to maneuver in thick brush.
We are testing our latest innovation – an ultra-low pressure sprayer. It can operate at under 10 psi.
What are the advantages of ultra-low pressure? First, there is less drift. That’s because the ultra-low sprayer consistently produces medium size drops, not the very fine, drift-prone drops. Second, the drops from the ultra-low sprayer travel slower through the air. This means that the drops are less likely to bounce off the foliage of the target weed. Finally, the ultra-low pressure sprayer uses very little power. This means the sprayer can be lighter and still operate for a long time on a single charge. Here’s a video of ultra low pressure sprayer demonstrating the new dispenser.
We are offering a new product: a Stump Killer (see product). This product can be used right out of the bottle, i.e., no mixing required. It is perfect for those with a small number of weed trees to control. Here is our video explaining how to use it:
Here is a link to the video: How to Kill a Tree Stump Fast – 5 Tips.
View this PowerPoint presentation: Targeted Weed Killer: Precision Foam Herbicide Delivery System. It explains the advantage of using foam herbicide: less risk to desirable plants because of reduced drift or overspray ; an increase in herbicide uptake because the foam keeps the herbicide in contact with foliage longer; improved visibility because foam is easier to see than liquid; and reduced herbicide waste because the precision reduces waste. We offer six different before-and-after examples such as the one shown in the following photos:
Note this: in this application, the chemical used was glyphosate which is a non-selective herbicide. If that herbicide had contacted the grass, it would have killed the grass too. As shown in the photos, that didn’t happen. This is a testament to just how precise you can be with the Green Shoots System. z