Boy do I know what your going thru. You almost need a bulldozer to pull these things out. I have a 60 foot long bed and they are everyhwere here too. I pulled out about half this yr to make more room for my WS plants. many came back. I hope by the end of next yr to have it gone. I love the smell. And I think it helps with mosquitoes, but if it stays its going to be in a container. I dont have the excuse that someone else planted it either :(
Tammy

We have selectively used Round Up in mixed beds to get rid of thistles that came in with the top soil/compost mix that we purchased by the truck load. Thistles also have very long root systems in comparison to what you see on top the ground.

I would suggest pulling out all that you can first and then treating the tops that come back up with Round Up. Spray only the leaves of the lemon balm and you should be fine. Round Up does not stay in the soil and it effects the root system of the plant, killing it. It has taken a couple of years, but we have almost rid the bed of thistles now. And, since we spray only on the thistles, we have not injured or killed any other plants growing in the same area. I just don't know what we would have done without Round Up in this situation. We've also used it successfully on dandelions that come up in the mixed bed. It's almost impossible to get all the roots of the dandelions when digging them out. And then they return, sometimes even larger than before. Everything else, we dig by hand.

Linda

I have the same problem and have just about given up! I haven't tried Round Up yet. One suggestion is to make sure you deadhead them or cut them down before they flower or set seed because mine re-seed prolifically as well as produce root runners.
Marcia

I had lemon balm and pulled it out by hand and thought I was successful. I hadn't seen any in a few years, then this year I see a plant right in the same location where I pulled it out. But it's just one plant and I'm pulling that out. Thankfully, I put the plant next to a cement walkway so it didn't get all over the yard.

I thought I had finally gotten rid of it, well, most of it, but they stuff just keeps popping up. I just keep pulling it out, when I can, and have kept it managable (for the most part). It's been years...

I have tried everything to get rid of this lemon balm. I have pulled roots, until I couldn't pull any longer. Used round up 3 times and the stubborn plant keeps coming back. I am now digging up the dirt and roots, hopefully this will get rid of it. A small amount would be nice, but it has circled my small pond out of control! If anyone has a better idea, please let me know!

Anyone giving away their lemon balm?!

cajun ...

use 100% RU .. in the very expensive applicator at the link.. snip a plant.. and drip it on the cut ... [that concentration is around 41%] .. and keep at it until it understand.. who is boss ... return unused product to properly labeled container ...

spraying is not really the way to go... in my experience ...

spraying is for self contained plants... what is probably happening here.. and i am too lazy to research it.. is that this plant is rhizome based.. which is basically an underground vine ... and if you spray on part.. it just resprouts a few inches back on the underground runner ... took me 3 years to kill PIvy due to this ... when it was all gone.. i found out.. there was a one inch underground running vine... [i am sure there are better scientific words for what i am suggesting]

good luck .. tenacity is usually the cure...

ken

Here is a link that might be useful: link