One year isn't long enough for girdling to kill them. Basically you are trying to starve the roots to death. I've got a 12 inch pecan tree in the middle of my greenhouse. It was cut back to the ground in the summer of 2004. All these years it's put up shoots under my weed barrier and still is. No light on the leaves to speak of and I cut them off several times a year. A healthy fruitless mulberry cut down at the same time nearby never sent up a single shoot.

I'd expect your girdled trees to decline over several years. You might check around asking about beaver girdled trees. There are lots of them in OK bottomlands and probably Kansas as well.

I'm not suggesting this is what is happening there- FN is right that girdling can take a while, although I'm surprised that there is decent growth on some of your girdled trees. However,I've seen trees survive girdling by goats that completely stripped the bark for the first 3' of trunk. How? Apparently the roots of the girdled trees were connected to the roots of other trees (this is a common occurance of roots growing into each other until the root cells merge).

The primary cause of death to a girdled tree is the gradual starvation of its roots. Because of the connections to uninjured trees the roots of the girdled trees were being nourished by the trees they were welded to. When I last saw these trees the girdling had been done 5 years previously. There was no bark bridge to explain their survival so I got that explanation from Linda Chalker-Scott.

Glysphosphate is only affective when it travels down the carbohydrate stream to the roots. If that's what you used the tree might have sealed off it's vascular system before you applied it.

Olpa - trees usually tend to get damaged like that in the wild (for instance, deer do a number on trees scratching their "rack" off in the fall).

I have read of "collering", which is almost the same thing, but it uses a metal band around the base of the trunk. IT takes about a year to work, but the tigher you put it on, the better.

The best part is, it does leave the roots in, making sure you dont disturb the soil.

Thanks for the responses. From what you guys are telling me, I guess what I'm seeing is not all that surprising.

It makes sense what you are saying, trees root graft, girdling starves the roots, etc. One thing I still don't understand is how the foliage of the girdled trees are obtaining water. I always thought the xylem carried water up to the foliage. I'm sure I girdled the trees deep enough to cut the xylem.

I suppose the only answer would be that the foliage is obtaining water from the core wood itself and I didn't know trees could do that for very long.

I've used picloram on the wounds as well as some 2-4D. Normally picloram works very well on trees (since it's designed to kill them) but elms are tough. I've sprayed elm seedlings with picloram and they laugh it off, but it does a good job on other seedlings. And it's done a good job applied to the wounds of other trees like hackberry and locust.

I don't know anything much about any herbicides beyond glysphosphate and 2-4-D.

I believe the sap wood can provide water for the tree further up. Girdled trees never seem to die for lack of water or it would be over very quickly.

Olpea, I had the same experience this year. Over this past winter I took my chainsaw and cut around the base of a big pine. I wanted all the pine needles to drop off before I felled the tree. The pine tree didn't die when I cut it two more times six inches deep. The tree put on new growth! What I see is the thick pine sap flows in the cut and must restore the sap flow. Some healthy looking pines just die off and when I cut the base I see borer tracks.

What kind of trees are you talkin about olpea?

"What kind of trees are you talkin about olpea?"

Canadian,

These are native trees that grow up everywhere around here and will quickly take over a field if it's not farmed, mowed or burned annually. Hackberry, Locust, Hedge, Red Cedar, Mulberry are the main ones, but to a lesser degree Maple, Cottonwood, and Elm will colonize a field too.

Hedge and locust are particularly problematic in a field because they pop tires when you try to mow. Cattle and wildlife will eat the hedge balls or seed pods of locust and spread the seeds all over the field, so that there are tons of seedlings that come up. Hedge at least has some redeeming benefit in that it makes good firewood and fence posts, but locust wood isn't good for much and the thorns are very bad.

I don't think thorny Honey Locust grows in Canada so you may not have seen one. The thorns can be up to 6" long. They are wicked sharp and generally cover the trunk. Cattle can go lame by stepping on them.