Direct Seeding Chestnuts....Sort of...

[cutman]

I'm sure it's too late, but RoundUp-glyphosate works by killing amino acid creating bacteria in the soil, so you can't kill a plant growing in your tree's roots by spraying it without affecting the soil where your trees roots are, and therefore your tree.

This is very wrong and not how glyphosate works.

Glyphosate - A Review

crops.extension.iastate.edu

 

[yoderjac]

I'm sure it's too late, but RoundUp-glyphosate works by killing amino acid creating bacteria in the soil, so you can't kill a plant growing in your tree's roots by spraying it without affecting the soil where your trees roots are, and therefore your tree.
Good old-fashioned salt is overlooked as a weed killer, salt water works great in the summer during dry times to kill the top of a tree, and you could put a small coke bottle half full of salt there and put the cut off stem of the Virginia creeper into it, it should suck the moisture out of the whole plant and dry out the roots.
But make sure you stand the bottle up, you could tape it to your tree cage.

So far, the creeper is dying and the chestnut is thriving. The current Roundup in the big box stores is not glyphosate. I added some gly and weed killer to the mix and sprayed the creeper staying outside the cage.

 

[yoderjac]

Here is a picture I took today of the the tree mentioned above and the Virginia creeper. You can see the creeper sticking through the cage at the bottom. It is completely toasted. The chestnut seems quite health.