Cut Stump Treatment for Killing Invasive Bamboo - Ask Extension
Hello,
A good friend of mine has requested help in removing a significant stand of bamboo on their property; I've been doing buckthorn and honeysuc...
Knowledgebase
Cut Stump Treatment for Killing Invasive Bamboo #855153
Asked November 12, 2023, 2:54 PM EST
Hello,
A good friend of mine has requested help in removing a significant stand of bamboo on their property; I've been doing buckthorn and honeysuckle removal with Washtenaw Audubon so they thought I might be able to help.
At least a decade ago, one of their house's previous owner planted running bamboo in beds in the front yard and along the West and North edges of their property; it seems like the front beds were at least partially contained, but the backyard has no containment considerations. For several years they have tried to keep on top of it with semi-regular cutting, but this has been insufficient. The bamboo is now spreading into their neighbors' yards, so they want a solution to remove it permanently so they can replant the area with native trees and shrubs.
By my estimate, there is roughly 6000 square feet of bamboo; some of the more recently cut areas are roughly 2' high, but other sections that were not cut this year are well above 20'. We've considered renting a mini-excavator to dig up the yard to get at the rhizomes, but we know they extend under fence lines and the costs associated are with using the heavy machinery are economically untenable.
Since mechanical removal is infeasible, we're considering a chemical approach. I've seen mixed reviews as to the success of spraying non-targeted herbicide on bamboo foliage (cut all bamboo back, let it regrow to 3' and spray with Roundup); I'm leery of spraying pesticides, especially since repeated applications over several years seem to be necessary.
As an alternative, I would like advice on the feasibility of using a cut stump approach to killing off the bamboo. My thought is to use a reciprocating saw with a demolition blade to cut any canes with a diameter of >3/4" just above the knuckle at ground level and immediately paint the cut surface with a 25% glyphosate solution using a Buckthorn Blaster. This would be done with a three person team: The first to cut, the second to paint the herbicide, and the third to remove the cut cane.
For the smaller canes, the intent would be to cut them to a height of ~4" using a brush-cutter, and then individually cut any canes larger than 1/4" at the ground level using hand trimmers and similarly apply the 25% glyphosate; this could be done individually.
While admittedly labor intensive, the approach seems the most likely to get the herbicide down to the rhizomes with the least amount of environmental dispersal. Has such an approach ever been tried? Alternatively, is there a better chemical (that is available to unlicensed civilians) to use than glyphosate (from either a human/environmental safety perspective, or from an efficacy standpoint)? Further, what are the implications for future replanting? I understand that glyphosate decays relatively quickly in the soil, but will it remain concentrated in the rhizomes for an indeterminate length of time if they aren't physically dug up and removed? We don't want to eradicate the invasives only to be let with large swaths of barren ground for years after.
Thank you.
Washtenaw County Michigan
Expert Response
Andrew, this is a tough situation, but it seems like you have a good grasp on why that is.
The cut stump method can work for bamboo, but you should be using a glyphosate product that is more concentrated...40% or greater glyphosate (e.g. Roundup Super Concentrate, but there are cheaper generic alternatives at places like TSC).
Glyphosate in the rhizomes of the treated plants is not expected to cause issues for future plantings, but you want to make sure the bamboo is controlled sufficiently before investing in new plant material.
It has been a while since I have had a bamboo inquiry, but I have a write-up that is still relevant I will include below. Some of it you've already covered, some of it may be new. There's also a great website with a video dealing with bamboo specifically from the University of Maryland; not sure if you've seen that.
Please take a look at let me know if you have any other questions.
_______________________________
Here are the options as I see it. #1 kill all of the bamboo in all yards. This is easier said than done. #2 create a physical barrier in the soil to prevent the rhizomes (those underground stems) from penetrating into your property. #3 is to treat what comes up every year to suppress it, knowing it will be a yearly battle.
If option #1 is possible, check out my information in option #3 and apply to all. All of the sources I have looked at suggest that it may take a couple years to completely get rid of the bamboo and that combined efforts including removing rhizomes, mowing, and multiple herbicide applications together may provide the most effective long-term control.
Option #2. For installing a barrier there are some good instructions and a video on this website from the University of Maryland.
https://extension.umd.edu/resource/containing-and-removing-bamboo
Option #3. If the plants around where the shoots are coming up are one that you don’t care about or could be replanted later then glyphosate (Roundup Super Concentrate) is probably the safest first option. This can be applied either as a direct application into the hollow space of cut stems (which may be most effective) or as a spray to the leaves (most likely to drift onto other plants).
When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, glyphosate is relatively safe in the environment when used as labeled. It adsorbs strongly to soil in most cases (i.e. clay and organic matter), allowing even sensitive crops to be planted shortly after application; meaning no carryover issues are expected. Fourth, glyphosate alone can take up to 14 days to show full activity under ideal growing conditions. Retreatment of the area may be needed depending on the degree of infestation. Glyphosate is most effective for perennial control in the fall but can be applied anytime the plants are actively growing (temperatures consistently above 50F). For woody species, periods of heavy sap flow in the spring may not be effective times to treat. Finally, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).
The Roundup.com website does have some information that might be useful about applying glyphosate to cut bamboo stems.
https://www.roundup.com/en-us/library/specific-weeds/what-bamboo-and-how-do-i-control-it
There is a more potent option, but only for bareground areas where you desire no vegetation…Another active ingredient that has been shown to be more effective in controlling bamboo is imazapyr. This can be found in combination with glyphosate in the product by Ragan & Massey called RM43 Total Vegetation Control (available at TSC, there may be other products as well). You can also find imazapyr in Ortho Groundclear Year Long Vegetation Killer (imazapyr + pelargonic acid), but I'm not sure if the pelargonic acid might cause some antagonism (i.e. reduced efficacy). These products will prevent the germination of anything new you plant for a year or more (according to the label, usually more if it is a clay soil). These products can also cause damage to desirable trees and shrubs if applied over the root system.
The cut stump method can work for bamboo, but you should be using a glyphosate product that is more concentrated...40% or greater glyphosate (e.g. Roundup Super Concentrate, but there are cheaper generic alternatives at places like TSC).
Glyphosate in the rhizomes of the treated plants is not expected to cause issues for future plantings, but you want to make sure the bamboo is controlled sufficiently before investing in new plant material.
It has been a while since I have had a bamboo inquiry, but I have a write-up that is still relevant I will include below. Some of it you've already covered, some of it may be new. There's also a great website with a video dealing with bamboo specifically from the University of Maryland; not sure if you've seen that.
Please take a look at let me know if you have any other questions.
_______________________________
Here are the options as I see it. #1 kill all of the bamboo in all yards. This is easier said than done. #2 create a physical barrier in the soil to prevent the rhizomes (those underground stems) from penetrating into your property. #3 is to treat what comes up every year to suppress it, knowing it will be a yearly battle.
If option #1 is possible, check out my information in option #3 and apply to all. All of the sources I have looked at suggest that it may take a couple years to completely get rid of the bamboo and that combined efforts including removing rhizomes, mowing, and multiple herbicide applications together may provide the most effective long-term control.
Option #2. For installing a barrier there are some good instructions and a video on this website from the University of Maryland.
https://extension.umd.edu/resource/containing-and-removing-bamboo
Option #3. If the plants around where the shoots are coming up are one that you don’t care about or could be replanted later then glyphosate (Roundup Super Concentrate) is probably the safest first option. This can be applied either as a direct application into the hollow space of cut stems (which may be most effective) or as a spray to the leaves (most likely to drift onto other plants).
When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, glyphosate is relatively safe in the environment when used as labeled. It adsorbs strongly to soil in most cases (i.e. clay and organic matter), allowing even sensitive crops to be planted shortly after application; meaning no carryover issues are expected. Fourth, glyphosate alone can take up to 14 days to show full activity under ideal growing conditions. Retreatment of the area may be needed depending on the degree of infestation. Glyphosate is most effective for perennial control in the fall but can be applied anytime the plants are actively growing (temperatures consistently above 50F). For woody species, periods of heavy sap flow in the spring may not be effective times to treat. Finally, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).
The Roundup.com website does have some information that might be useful about applying glyphosate to cut bamboo stems.
https://www.roundup.com/en-us/library/specific-weeds/what-bamboo-and-how-do-i-control-it
There is a more potent option, but only for bareground areas where you desire no vegetation…Another active ingredient that has been shown to be more effective in controlling bamboo is imazapyr. This can be found in combination with glyphosate in the product by Ragan & Massey called RM43 Total Vegetation Control (available at TSC, there may be other products as well). You can also find imazapyr in Ortho Groundclear Year Long Vegetation Killer (imazapyr + pelargonic acid), but I'm not sure if the pelargonic acid might cause some antagonism (i.e. reduced efficacy). These products will prevent the germination of anything new you plant for a year or more (according to the label, usually more if it is a clay soil). These products can also cause damage to desirable trees and shrubs if applied over the root system.
