Round up is not very effective on vinca because it "slides" right off the vines. Vinca is a very invasive and aggressive plant.

I had a bank of the big leaved vinca that I eventually pulled out jut by being stubborn. I didn't want to spray. If you start digging and pull after every rain, you can eventually eliminate it. It might be harder for you as the roots are wedged in the stone cracks. Good luck!

It looks like an area with no plants you'd want to keep. You could smother the whole under thick cardboard, topped with mulch. You'd need to monitor around the wall closely, quite often, until you stopped seeing sprouts there. If you feel like moving the pavers (assuming they're not mortared,) that would allow you to smother under that in a solid sweep, without worrying about so many likely sprouts at the base of the wall. The grass looks too sparse to be worthy of time spent mowing it, or prevent mud after a rain, I'd be done with that little stripe of it too.

I don't really understand that spot generally, from what's visible in the pic. Looks like the wall may not be in a great location, but it does look like the land slopes away from it.

I agree with purpleinopp on the smothering idea. This is a great time of year to do it.

Here is a link that might be useful: A Weed by Any Other Name is Still a Weed

I you want a quick fix get a broad leaf weed killer, one with 2-4-d will get most of it on the first pass, then just go back and spot spray the stragglers.
Round up works best on grasses and sedges.

I forgot to add that if you will put a drop or two or three of Dawn dishwashing liquid , it will make it stick and kill better.
That makes broadleaf weed killer and Round up work better

It could be that my computer screen isn't giving me an accurate picture of your vinca, but it looks more like aegopodium to me. That stuff is SUPER invasive. Roundup (or any glyphosate product) should kill it off. If you don't want to replant the area for at least three months, there is a new Roundup called Extend that will surely knock it (and everything else) down for 3-4 months. DH is a chem engineer and says that Roundup totally dissipates in a day and it won't remain in the soil. Just don't use it near aquatic life. Good luck with your new home and congratulations!

Well, it has remained under control with pulling it. here is a better picture of it.

Thanks for that picture, it is a lot better. Good job with pulling it. You must have really kept after it. Cheers.

I also have noticed that the waxy surface of vinca sheds herbicides, but would string trim the area, or mow it, enough to expose surfaces of cut leaves and stems, to allow the Roundup to penetrate. Will be surprised if that does not work. In fact, I will try it next time I am string trimming my lawn, on a portion of vinca.
Since I am not going to try to get rid of the 4th of an acre of vinca I have, I have just gone after it with patience and a hand held claw tool between the Azaleas and the walkway and behind them. Very tedious, time consuming and dirty work. A measured segment when convenient, so I do not get discouraged. Satisfaction keeps me going, and I have a wood chipper that will even chop up the wheelbarrows full that I have been digging up. Did the same in a bed around daylilies and azaleas, another place. It is not back.

The Vinca was, actually, climbing up into and through the Azaleas and damaging them. I only did from one light to the next at any one time.

Hello to all, I just ran across this thread. Bogturtle, is that vinca major in your picture? The reason I'm asking is I'm wanting to use vinca minor 'illumination' in a bed with boxwoods, azaleas and Lilly turf. I haven't heard of vinca minor being as aggressive (toward bushes) as you have described. Does anyone have experience with 'Illumination' or other vinca minors vs. Majors?

Vinca minor and what probably used to be something else underneath. IDK.

As much as I like illumination, I think I'll steer away from it now. Thank you for your input.