Have any of you ever planted wisteria?

[Billybob]

Copper kills plants, try driving a penny into the freshly cut stem.

 

[BadgeBunny]

Have you tried cutting down the wisteria, then immediately spraying Roundup on the cut stem? I'm not a big fan of pesticides, but that spot application might do the job.

Yep ... And on the trumpet vine too.

Copper kills plants, try driving a penny into the freshly cut stem.

Now THAT I haven't tried ...

 

[Perplexed]

Copper kills plants, try driving a penny into the freshly cut stem.

Hadn't thought of this, but it makes sense, as copper will kill aquatic vegetation (as well as invertebrates!) But I'd think the penny would be more effective if it's oxidized. Leave the penny out in the weather a couple weeks, especially if it rains, then bury it in the stem.

 

[Billybob]

Not absolutely sure it will work but some herbicides are copper based and I remember my dad telling me long ago that they used to drive copper nails into trees to kill them.
Considering what pennies are worth today it's not too costly to try.
Copper powder might be a more effective application.