This video explains why a Norway maple remained green all summer after i girdled it. I like the tools you used as well. I used a small folding saw and cut twice around the trunk 6 inches apart and then used a brick Laying in the woods to chip the bark away. Thx for this video on a wise subject to support our ecosystems.

Great video. We have invasive albizia trees on are property. We can use this strategy for killing the trees. Thank you for the video.

It's good to see you again Jeff

Fantastic! Great to see ring barking being used. It's such a shame to see every unwanted tree being felled, logged, and taken somewhere else and completely wasted! About how long do you think is the typical delay between ring barking a tree, and it becoming productive with insects and woodpeckers?

Super well done Professor Jeff! As a person who also creates content, I know how much work you did to prepare for and create this video and you did a fantastic job! Also, you narration was flawless! I really enjoyed watching this video and learning something new. I give you a 12 on a scale of 1 to 10! Really fantastic Jeff!

I really enjoy these videos! Informative and interesting! Thanks!

Jeff, I work with more vigorous invasive trees that need to be taken out when the trunks are smaller. We use a similarly inexpensive toolkit: a carpet knife, a putty scraper, soapy water, rubbing alcohol, and a scrubbing pad or scrub brush. I hope you don't mind if I use your video to complement my own in a workshop I'm giving later this week. You have reached the same conclusion I have: The key step of girdling, which is removing the inner bark, works best with a dull tool, not a sharp one. You want the tissue to lift itself off the sapwood, not get sliced away. I do have a few comments that I hope you'll find helpful. First, I suggest you add a final step of scrubbing the exposed sapwood. A little field study I did (with the guidance and help of an actual scientist) showed that removing residual inner bark tissue-phloem and cambium-from the surface of the sapwood puts an end to reconnection across the girdle. We tested four different ways of removing that tissue: scraping down to hard wood (the mature sapwood); scrubbing with water; scrubbing with soapy water; scrubbing with rubbing alcohol. All worked the same, provided the work was done thoroughly. (In each case, we saw the same number of failures, and each failure was because an unnoticed strip of inner bark, however thin or slim, had been left in place.) But in practice since our study, my volunteers have told me that scraping is hard work and triggers repetitive motion injuries and that scrubbing with water takes longer than scrubbing with either soapy water or rubbing alcohol. I have found that scubbing with soapy water and then rubbing alcohol is easier and gets the volunteer to be more thorough. The soapy water releases the tissue better, so it scrubs away more easily. The alcohol releases tissue in its own way and dries the outermost tissue, increasing the chance that the inner bark tissue dies. Doing two steps rather than one makes me look at the gap carefully twice, so I'm more likely to notice any trace of tissue I was about to leave in place. Second, on the width of the gap, I have found that in my area, invasive trees are remarkably alike in that, regardless of size, new tissue grows into the gap from the top at a rate of about half to three-quarters of an inch a year. Your six-inch gap is great because it's easy to achieve with your tools, but in the final scrub, cleaning a 2- to 3-inch-wide band all the way around the trunk is enough to ensure that the tree dies. Third, on the tree that grew new bark along the edge of a wound, removing the new bark isn't quite enough. As the tree recovers, from the outside we see it cover the wound with a "patch" of new bark. But a better description of what is happening is that the tree is starting to grow a new trunk, parallel to the old one-including new inner bark behind the old live tissue and on top of the same layer as the exposed tissue of the wound. If you cut the healing edges of the wound away, you will find that there is a layer of bark wedged back in there and a layer of green tissue that might extend all the way around the trunk. How far it extends depends on how long that wound had been closing. If at all possible, I avoid girdling at a scar. I'll work above it or below it instead. Fourth, people ask me and you didn't mention it: What's the right height for girdling the tree? As you've shown, it doesn't have to be the bottom. It just has to be below the lowest leaf on its trunk. For safety, it should be at a height where you feel comfortable working. You pretty well demonstrated that. And for ease and success, it should be on a section that is close to being round as a pipe and has no knots or branches. The trees I work on most-Ligustrum lucidum, or glossy privet-have a tendency to form long concave sections along their trunks. Digging the tissue out of that depression can be a pain. If I have no choice, I can make it work, but I try to avoid those indentations. Fifth, if you haven't tried this, you might let the new basal shoots grow on a few trees and see what happens. In my experience, if the girdle is good, those shoots grow long and limber but never harden off. They die before the top does. If they start putting on girth and hardening off, either the girdle has bridged or a trunk or branch was left ungirdled. I can see that difference from ten or twenty yards away. So if I'm walking through a wooded patch after my volunteers have girdled it, I can tell which trees I need to inspect by glancing at those basal sprouts. If they're wimpy, no need to look more closely. If they're putting on bark and girth, I'd better get over there. I fix the problem, strip off the shoots (often I girdle the woody shoots), and go on my way. Finally, when you see a tree budding out weakly at the beginning of the season after it was girdled, chip away or scrape the bark anywhere below the girdle. After doing this for several years, I finally realized that the root system dies before the top does. The tissues in the top will still have stored water in them, will use that stored water to leaf out and even bloom, and will wither as soon as that water is used up. So if you need to cut a tree down as soon as it's dead, you don't have to wait for the top to look completely dead. The bottom will die first. The trees we've girdled include glossy privet (L. lucidum), Chinese privet (L. sinense), quihoui privet (L. quihoui), Chinese tallow (Triadica sebifera), Chinese pistache (Pistacia chinensis), and chinaberry (Melia azederach). Unlike the others, Chinese pistache and chinaberry put out basal sprouts that thrive even when the girdle is fine. I just strip those back to a well-spaced few-maybe one for every 3 to 4 inches of the original trunk's girth-and I let those grow one season and then girdle them. Sometimes I have to do that twice; one tree has made me do it three times. But they die completely eventually. This is far better content than other demonstrations of girdling I have seen online. For larger trunks, I am definitely adding a prybar to my girdling toolkit!

Great demonstration of how - and when - to girdle trees. We have Privet choking out our native oaks, cedars, elms and others in our many walking trails and in a nature preserve near me. I have been trying to find a little tool I saw someone use that removes about an inch or so of outer bark from trees, but can't find it. Your video shows me how to use common tools that I already have to do the job. Thank you!

I got my answer to my question "Why not just cut into the bark all the way around, do you have to make a wide ring around the tree?? Ans, because, the bark could grow back. Where I am at, it is recommended girdling the second week in Jan. I'm going to give this a try

Thanks best video for what i need to do . Small , maybe even saplings. Plus a spraying happy neighbor . I will try to refrain from further comment about that . Thank you for the detailed instructions. Have a good day.

That's so interesting! Too bad we can't use this option in town. I'm excited to see you plant black walnut - not nearly enough of those left standing these days!

Super video Jeff. Greetings from England. I enjoyed this video. I even liked the video of ring necked ducks. Over in England we receive tufted ducks but are the same colour as the males but don't show a ring

Well explained sir, long live like a king.

Good to know, very informative video, thank you. Now, if you can just tell me how to kill Wisteria vine, lol. We are taking our backhoe and digging up a fence and the root ball of the Wisteria, which has ruined the fence btw. Hoping my Wisteria issue will be resolved soon, but a friend of mine has somewhat of a similar problem with the same type of vine in her yard.

Hey Jeff I have a huge tree very close to my home if I girdle it will it fall or just stop growing..

Dear Jeff, I have 2 questions : - Will it be more difficult to do this when the bark is not really dry (in spring)? - Is Douglas Fir's bark hard to peel with this method? Thank you.

I've always wondered if insects can do that and then it provides nesting for woodpeckers other cavity birds, just part of the ecology.

Good to know.

If you want the tree dead, why is it important not to go past the inner bark so the leaves can still grow?

How many day it takes killing thos tree??

Why not just cut down it, generally they are removed for public safety?

I feel bad for the trees that will be murdered!!.If the trees are dead, how do they still stand?They will eventually fall, won't they?

Killing any tree or plant besides weeds is pure evil! I hate it when people kill the very plants and trees that produce oxygen for everyone. I don’t understand y u can’t just sell the tree or move it to somewhere else out of the way