Stump Killer – Use It this Winter and Get a Jump on Spring and Remove Unwanted Trees and Bushes

You have an unwanted tree growing vigorously in the wrong place – in the middle of a flower bed or in a native grass planting or next to a building foundation.  You know you need to remove it.  Winter is actually a great time of year to do this.  Herbicides work fine in the winter if applied correctly.  See Reinartz 2002.

If you simply cut the tree or bush down, you will soon get something far worse in the spring: a multi-stemmed bush like the one shown below on the right side.

Buckthorn stump with re-sprouts

treated, dead stump on left; untreated, live stump on right which is sprouting vigorously

There is a simple way to prevent this from happening: use the Green Shoots Foam Herbicide System to precisely apply a concentrated herbicide to the stump immediately after cutting to kill the stump.  So here is what you do.

  1. Cut back the tree or bush – If it is a big tree or bush, I typically cut off the upper branches first and leave a tall stump anywhere from knee to shoulder height.  Clear out the branches so you have room to work.
  2. Prepare the Foam Herbicide Dispenser according to the instructions.  Be sure to read the herbicide label.
  3. Cut the stump close to the ground – try to cut it within 2 to 4 inches of ground level.
  4. Immediately apply the foam herbicide to the cambium layer of the stump.  This is a thin layer of live inner bark  just inside the outer bark.
Freshly cut stump of weed tree

Freshly cut stump of weed tree

Foam herbicide applied to cut stump in winter

Foam herbicide applied to cut stump

The Green Shoots Foam Herbicide System has several advantages over standard herbicide sprays:

  1. Precision – This is critical when you are applying to the narrow ring of live inner bark less than 1/10 inch thick. With a liquid spray, the application is so imprecise – you may miss your target.  At the very least, you will waste herbicide trying to hit the target.
  2. Less Drip – The foam herbicide sticks to the target and will slowly soak in.  Liquid sprays will bead and drip off the target.
  3. Visibility – the foam is visible for some time after the application.  This helps in identifying what part of the target you have treated.

For more information about the Green Shoots Foam Herbicide System, visit the Green Shoots website.

Killing Invasive Thistles and Other Weeds using Large Foam Herbicide Dispenser

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

Extension nozzle used to apply foam herbicide to invasive thistle

Extension nozzle used to apply foam herbicide to invasive thistle

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.

New Large Handheld Foam Herbicide Dispenser – Launches in March, 2014

Large Handheld with Foliar Nozzle

Large Handheld with Foliar Nozzle

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!

Best time to kill many perennial weeds and invasive plants with weed killer? Late Summer and Autumn!

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.

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Aquatic foam herbicide applied to invasive knotweed in September

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Foam weed killer applied in September to invasive crown vetch. Note that the crown vetch has been bunched into a pile to improve targeting.

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.

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Foam weed killer applied to Canada thistle in late October after a frost.

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.

Lampe Presents on Rhizome Injections for Invasive Knotweed at Upper Midwest Invasive Species Conference in La Crosse, Wisconsin,

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.

Sale of Small Quatities of Concentrated Glyphosate – Ideal for cut stump and frill treatments on Woody Brush and Invasive Weed Trees

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.

Autumn and Early Winter – Great Time to Use Herbicides to Kill Invasive Perennial Weeds such as Woody Brush, Trees, and Plants with Rhizomes using Cut-Stump, Frill, and Bend-and-Treat Techniques

Applying Foam Herbicide to Cut Stump

Application of Foam in Cut Frills

Application of Foam Herbicide on Bent Stem of Japanese Knotweed

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 Tall Weeds with Weed Killer – Foam Herbicide for Foliar Applications to Avoid Drip, Drift, and Off-Target Spray

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.

Using the Green Shoots Precision Foam Herbicide Dispenser to Control Common Lawn Weeds Like Exotic or Invasive Thistles

Application of Herbicide Foam to Bull Thistle Rosette

Dead Bull Thistle 8 Day after Foam Herbicide Application

Small Green Shoots Foam Herbicide Dispenser

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.