Why can't I kill bamboo roots with bleach?

Question

This is a follow-up to my first question on the gardening stack exchange. Unfortunately the horrid bamboo continues to plague me this summer. To the point that I'm actually considering packing up and quitting this home: I really wanted a yard with minimal maintenance needs, and now with the bamboo's invasive spread, I seem to have ended up with the very opposite, taking away precious time from the more important things I ought to be spending it on.

A suggestion from the linked post was to apply glyphosate to the ends of exposed roots. Before trying that, I wanted to try a "less toxic" approach because of proximity to kids and carcinogenic concerns. A friend suggested offline to soak the exposed ends of roots in saltwater; the theory being that the saltwater would soak through the root system and kill the plant. I thought to go one step further and try soaking the exposed root ends in bleach, thinking to myself "there's nothing more caustic than bleach - surely soaking a plant's roots in it will kill it." Picture below:

So I filled a couple of spray bottles with 100% bleach, and dipped exposed ends of bamboo roots in it. I taped up the tops to ensure no spillage onto innocent soil. It's been one week, now, that the roots have been soaking this way, and there is no change in appearance to the bamboo roots! I expected some manner of shriveling or necrotization - but there's no change I can perceive at all! So I can't tell if this treatment is having any effect at all.

The reason I'm attempting this is that the root system has grown under the very thick hardscaping that covers most of the area of concern. So it is practically impossible for me to dig up the roots that have grown under in this manner. So I was hoping to find some way to "kill the root system upstream".

So, my questions for knowledgeable gardeners, horticulturalist, and maybe biochemists are: is soaking the exposed end of a bamboo root in a noxious liquid a viable method of killing a bamboo's root system? If so, was bleach a good choice? If so, how long should I continue the existing soaking treatment, and will I eventually see a visible change in the root system so I can know that it's dying? If bleach isn't the right thing to try, is there something else I ought to soak the roots in that will have the intended effect of travelling upstream and killing the root system?

I'm surprised that you think leaving bottles of bleach around in your garden for long periods is more "risk free" for your kids than using glyphosate - but each to his or her own. — alephzero, Aug 27 '18 at 17:01
@alephzero - Yeah...I dunno. It's probably nothing more than misplaced "familiarity" with bleach, because bleach is something most everyone has grown up with as a cleaning/disinfecting agent, so it feels "less dangerous" than glyphosate, which I have no familiarity with, so it feels foreign/exotic/dangerous. The kids are physically barricaded from the premises, so either way, there wouldn't be direct exposure, but because of what I just said, I suppose I felt safer with trace residue of bleach than glyphosate...I'm only grateful to be corrected if you know differently...? — StoneThrow, Aug 27 '18 at 17:09
Use glyphosate no one's going to get cancer from it that's just silly. You need something systemic and that's the best there is. — Rob, Aug 27 '18 at 19:38
Step 1: Buy Flamethrower Step 2: Identify Bamboo Step 3: Carnage — Mihkel, Aug 27 '18 at 16:43
@Rob - I actually thought you had a helpful, on-point answer (other than the "brain on your neck" comment which came off as unnecessarily snarky, but maybe I'm inappropriately projecting emotion onto raw text), so I hope you consider re-posting some version of it. Online, I've read to brush the tips of exposed roots to glyphosate - is that really all that's needed, or ought I soak the roots long-term similar to how I've been soaking them in bleach? — StoneThrow, Aug 28 '18 at 16:59
@StoneThrow Yeah the answer was banned because someone reported it. Not sure how/why that works the way it does but apparently a post can be banned without proper cause. In any case, glyphosate should work well for you. — Rob, Aug 28 '18 at 17:06
@Rob "glyphosate should work well for you": you recommend/know long-term soaking or just brushing the tips? — StoneThrow, Aug 28 '18 at 17:07
@StoneThrow Products such as: https://www.amazon.co.uk/X2L-GALLUP-Non-PrOFESSIONAL-GLYPHOSATE/dp/B071JPLQCM/ref=as_sl_pc_as_ss_li_til?tag=portingale-21&linkCode=w00&linkId=0611c4a29205d7e4687a4e6166aa229e&creativeASIN=B071JPLQCM tend to come with pretty simple instructions for application. Try your method for application on all of the exposed roots using the mixing instructions for a spray solution which will be detailed on the product. Or maybe it would be easier to just spray them and tell everyone so they know not to go touching herbicide. — Rob, Aug 28 '18 at 17:17
@Rob - I've been reading about glyphosate following our conversation. Most articles say glyphosate only works when exposed to leaves/shoots, and some articles go so far as to say it will not have an affect if applied directly to roots. I imagine your suggestion is effectively "doesn't hurt to try" applying it to the roots anyway, and I'm certainly willing to. My question is: is the glyphosate concentration important? I've seen products with varying concentrations and my impluse is "the higher the better" but I wonder if you know better? — StoneThrow, Aug 29 '18 at 17:09
@StoneThrow I addressed the issue in my original response. I imagine it will take 2x to 3x longer for the product to be effective when exposing only the roots. That being said I would stick to the lowest amount of water suggested for the mix, dont use hard water and dont use dirty water. I have never had to kill a plant with a leeching agent through the roots upward before.. so it is a bit of a guessing game for me. Do yourself a favor and get as close to the root sock as physically possible to apply the product. — Rob, Aug 29 '18 at 17:40

Bamboo · Accepted Answer · 2018-08-29T18:37:00.830

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First, let me just say that the bleach treatment will do nothing much in regard to the roots of the bamboo - the majority of the root system is widespread under the hard landscaping, and is inaccessible. Translocation of the bleach throughout the root system is not going to happen.

Second, the reason given in another answer (now apparently removed) as to why sodium chlorate was banned in Europe, isn't why it was banned; it was banned because it's a known fire hazard, it affects the ozone layer above the planet but primarily, it's a useful ingredient in bomb making https://www.gov.uk/government/publications/supplying-explosives-precursors/supplying-explosives-precursors-and-poison. I don't suppose I need to say more about that, given the terrorism which exists... it is still available under licence in special circumstances.

The other problem with sodium chlorate is, it works best if you can apply it to green parts of plants, as does glyphosate. It will kill through the roots, but given the rhizomes from the bamboo have run under the hard landscaping, you'd practically have to saturate the whole garden area with it in an attempt to get it to translocate to the rhizomes under the paving, and it would kill absolutely everything else as well. You could try repeatedly applying high strength glyphosate (the sort used as stump killer) to the roots you can actually see, but the trouble is, there's a lot of roots you simply can't get at, and repeated, ongoing treatments aren't something you say you particularly want to do. Fact sheet here for sodium chlorate http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/sodium-chlorate-ext.html

There is, frankly, no quick and easy answer to this - if you bought your property, there may be some legal recourse with the seller because of this inherited problem. If you are not the owner, it's difficult, unless you can persuade the owner to deal with the problem. Otherwise, apart from calling in professionals to deal with it (they should have access to products amateurs don't), it may be that the only recourse you have is to insert a root rhizome barrier vertically to a depth of 18 inches at the edges of all the paving, which will prevent the rhizomes from spreading past it. It will still be under the paving though, and I suppose it's possible it may appear between any cracks that exist, or possibly through the grout if there is grout between pavers.

UPDATED ANSWER

In response to your comment - glyphosate might work if you spray green regrowth, but to be honest, I doubt it will kill all the rhizomes under the hard landscaping. There is information here https://homeguides.sfgate.com/weed-killer-bamboo-49276.html which gives proposed methods of dealing with it - herbicides that kill grass might be as effective as glyphosate, but whatever you use, the link makes it clear that it will be an ongoing treatment programme over some years, and that's for bamboo with accessible roots. As I said, a difficult problem to solve quickly...and why I suggested using root rhizome barrier. Bamboo is the gift that keeps on giving, whether you want it or not...if one of the many varieties which run is planted. There are, though, a few that simply form clumps and don't run in this way.

edited Aug 29 '18 at 18:37

answered Aug 27 '18 at 17:47

Bamboo

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Well if he's not just trying to kill the roots that are exposed then what he needs is a systemic herbicide. Also, Eurupe is the only place that I am aware of (on the globe) that has banned saodium chlorate. Also, from the research I have gathered it was banned due to possible soil contamination not bomb making. Glyphosate, is the best systemic herbicide I know of so the OP should go with it. – Rob Aug 27 '18 at 19:36
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@Rob with respect, I live in the UK (currently in Europe) and you don't. However, even if you don't agree, I don't see why you marked me down...and there appear to be gaps in your knowledge anyway. You might be interested to know (or not, I'm guessing) it was banned in Canada back in 2005 under the Montreal Protocol because of its ozone depleting effects... as for glyphosate, 'it works through the green', Paradise is better - but only if you can access the roots, which obviously is not possible in these circumstances. – Bamboo Aug 27 '18 at 19:56
I marked it down because you said frankly there is no easy answer when there certainly is and that's to use herbicide. Also, he has access to the roots look at the picture. That's what systemic herbicides do. You only need to touch part of the plant for it to spread throughout the entirety of it. I wont start here with you into your flawed logic. Living in an area doesn't mean you have more knowledge of it than I do especially in this day in age. – Rob Aug 27 '18 at 20:14
@Rob - you're entitled to your opinion - but so am I. And my qualifications are actually in horticulture, unlike yours. As for the downvote, well, it''s not really a big deal, but still worth mentioning nonetheless. – Bamboo Aug 27 '18 at 20:16
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In the interest of being reasonable here is where I got my information about why the substance was banned in your country: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/318215/hpa_Sodium_chlorate__General_Information_v1.pdf – Rob Aug 27 '18 at 20:19
@Rob yea, I know what that says - when I've got time, I'll seek out the other info I found re terrorism... I had it earlier today. But clearly, its not just Europe, Canada withdrew it before we did... – Bamboo Aug 27 '18 at 20:26
@Rob https://www.gov.uk/government/publications/supplying-explosives-precursors/supplying-explosives-precursors-and-poison - this is one of the reasons it was withdrawn from general sale and its one of many links I could provide to back up what I said... – Bamboo Aug 27 '18 at 20:58
@Bamboo - I'd like to pose this question to you since you mentioned you have horticulture qualifications: I'm wanting to try glyphosate since the consensus is that the bleach treatment is ineffective. Most articles I've read say that glyphosate only works when applied to leaves shoots and has no effect if applied directly to roots. Assuming that is true, will application to leaves/shoots "seep down" to the roots and kill them? You probably already understand my desire to affect the roots in order to prevent further spread and resulting physical damage to my property. Thank you. – StoneThrow Aug 29 '18 at 17:13
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See updated answer... – Bamboo Aug 29 '18 at 17:54
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@StoneThrow you might be interested in this https://youtu.be/0WSCXz_SxbY as a possible deterrent – Bamboo Aug 29 '18 at 20:50
@Bamboo - I'll try make this my last question to you on this topic, to not unduly occupy your time: as discussed already, bleach will not translocate through a bamboo's root system to widely poison it. Is this because bleach is more viscous than water so will not be absorbed? If so, do you think my friend's original recommendation to soak the root ends in saltwater (as noted in the original posting) has any merit? Might saltwater translocate through the root system, and if so, would it have any detrimental/killing effect on the roots? Btw, your video re-made my wariness of glyphosate. – StoneThrow Aug 30 '18 at 17:34
Yea, not too sure about glyphosate myself any more... you could try a strong salt solution,used in the same way as the bleach, but I don't believe it will translocate, it will just kill the one you immerse in it. Strong salt solution will kill absolutely everything, including all life forms in the soil, and if you were able to access the bamboo's roots, and saturate with it,it would likely kill them. But its a bit like using agent orange, and you can't access all the roots anyway. – Bamboo Aug 30 '18 at 18:30
I forgot to say- bleach is a disinfectant - it kills bacteria and viruses, its not designed to kill plants,though of course, if you splashed it on foliage,it would likely cause some damage. – Bamboo Aug 30 '18 at 19:10

score 1 · Answer 2 · answered Aug 27 '18 at 16:58

I can appreciate your situation. While I do not have bamboo, I do have milkweed, mares tail and various thistles to contend with in an open garden which to some extent present a similar problem. They are extremely persistent; they set up deep underground networks and seem to communicate with each other, sharing ideas and nutrients in their duty to expand and prosper. Hitting the growing ends is only partly successful; they have the ability to remain in a sort of stasis, waiting for a new opportunity to exploit resources. They have thick fleshy roots that are capable of storing food over long periods and can survive drought and heat better than other shallow rooted plants.

I don't see that the root tissues have any incentive to move the poison from the cut ends through the tissues; what is doing some good is to expose the root hairs which will have a desiccating effect.

First rule I think is to deny the root system every opportunity to photosynthesize and make additional food. If we can be sure of this then we know it is in stasis. The root system then transfers resources to the most likely place that it can expand. I sense that in your location (unlike mine) you can box the critter in - if there is no sign of shoots then any roots that appear must come from transfer of resources, and by continuously removing those roots you must be depleting the entire system.

Your exposition of the problem sounds very logical and I have tried to present a logical solution that I'm sure you can appreciate. Let us know where my reasoning is leaky.

Thank you; unfortunately, with my situation, I don't think it's practical anymore for me to box the monster in - it's spread too wide already: it's gone both inside and outside my property, and - as mentioned already - underneath hardscaping. I suspect that if I installed deep barriers, the bamboo would eventually try to sprout in between the tiny gap between hardscape and the barrier. I will try preventing photosynthesis by trimming shoots as early as possible, and maybe try glyphosate as well. — StoneThrow, Aug 28 '18 at 17:05

score 1 · Answer 3 · answered Oct 18 '21 at 17:02

You cannot kill bamboo roots. Take it from me. My house was surrounded with 7 different types of bamboo on a very small lot (thanks to ex husband). I have literally had to rent an excavator 3 times to get the entire root system out. Sometimes the holes it left were 6 feet deep. Finally, I thought that I was through with it, since we treated all the holes with a weed killer before filling them in. Today, I've just found another 2 bamboo shoots coming up on my paved path!!! Guess it's time to rent another backhoe. It's the only way!

Why can't I kill bamboo roots with bleach?

3 Answers3