Brush killer very near trees

[yanmars]

I planted thousands of small white and red oaks about 25 years ago. For the most part an abject failure but that aside, for the ones that made it they are probably 15 feet tall or more but bases generally under 6 inches. The problem is some persistent weed trees have grown up very near them. So close I really cannot mow with a bush hog that close to the tree without damage to the tree or my tires.
I have used a heavy lopper to cut the trees down but they always come back. I have heavy duty chemical brush killer. If I lop them off and paint the small stump (they are generally under 2 inches) even if that kills them, because they are so close to the oaks and perhaps the roots intertwined will that also harm the oaks? There may be 10 to 15 of these shoots around every oak plus rose vines etc.
I have a 4 foot DR Brush type mower also but it has twin lighter blades and is not up to the task of cutting the saplings especially when I have to cut 6 or 7 at a time. It just overwhelms it. So it has been a lopper or chainsaw. The chainsaw gets clogged by grass, vines etc. often. Ideas?

 

[suburbanfarmer]

Brush killer will kill your oak trees. Sadly the only option is keep hacking away at the unwanted new growth

 

[mx1alex]

If you're only doing cut stump treatments with something like tordon then you are fine. Painting a 2" stump isn't going to hurt a 15' tall tree that's next to it.

 

[sea2summit]

I have about 10 goats and don't often recommend them for maintenance but in this case if the oak's lower branches are more than ~4' off the ground goats might be a good option.

 

[hslogger]

If you cut the unwanted brush trees off, assuming they are 1 to 3 inch diameter, you can brush the fresh cut with straight glyosphate on small paint brush. Or also drill small holes in the top and paint. That is the most benign treatment. Tordon, et al, they are all really toxic and will work. What ever you do, don't drip your treatment on anyting but the intended targe.

 

[Roadworthy]

That's a LOT of weed trees. I tend to address any I have in ones in twos. I'll push or pull them with my tractor, hoping to pull them by the roots like other weeds. When that doesn't work (and it frequently doesn't) the tree is at least loose enough I can dig next to it and identify major root locations. I'll cut one or two of these and try again to pull the tree. It's remarkable how easily some trees can be removed this way.

 

[ericm979]

Painting the small stumps should not affect the large trees as long as you're careful. For broadleaf trees I use 25% Garlon 4 in diesel. I have (carefully) soaked down poison oak vines that were running up trees I wanted to keep with this... killed the PO, didn't bother the tree. Garlon is good for this because it breaks down in the soil fairly quickly.

 

[kenmbz]

I use a toothbar to pop these out with the FEL. straight run, then come back from different angle. 1-4" are easy.
Regrowth takes a while here if the root ball center is popped.
Removing sunlight from the area helps too.
Had to clear out mature Bamboo stand and honeysuckle by the hundreds, Started with a handlebar brush cutter , got toothbar on tractor, much easier.

 

[i7win7]

Cut 2-3' high paint with vegetation killer. If it didn't die you have enough stump for a brush grubber.

Amazon.com : brush grubber

Deluxe option

 

[yanmars]

I have such a device but found it slow, also a tooth type bar on my front end loader. I can try that also.