Is that Vinca major? How are you doing the Roundup? It should be effective--might take a couple repeat doses, but you should get results. Spraying early to mid morning is most effective. That gives the afternoon sun time to wreck havoc.

Roundup works by blocking the circulatory system, if you will, of the plant. So the plant needs to be actively growing for the stuff to work.

I really doubt anything can kill a ficus hedge, though, short of a good hard freeze.

I hate to say this, but it looks like Japanese Knotweed. Could you give a close-up of a couple of different leaves?

If a plant has a large root system, it may take more than one dose of glyphosate.

Mature leaves are less likely to absorb the herbicide.
Glossy leaves are less likely to absorb the herbicide.

Putting it all together ...

You already removed the mature leaves, so this is fresh growth.

Add a small amount of dishwashing detergent to the sprayer (like 1/4 tsp/gallon, or a few drops for a hand-sprayer) to help it penetrate the waxy coating.

Apply the glyphosate once every two weeks until the stuff stops coming up. Hit every new sprout you can find, thoroughly.

It took me two growing seasons to get rid of a large established bed of that stuff ... spray, rake off the dead stuff, and the second year there were only a few stragglers.

If you purchase a plant poison concentrate you might need to add a surfactant, such as a soap or detergent, if the directions for that product state that needs to be done.
If the plant poison you purchase is ready to use it is that and does not need anything added because that can change the product and make it ineffective.
What color flowers and what color berries does this get?
Where in the United States are you? The zip code 91016 is for California which might make a difference in what plant that is.

I can only say that it isn't Vinca minor or major and it's not Japanese Knotweed. I don't know what it is, though.

This post was edited by floral_uk on Sat, Aug 30, 14 at 15:54

If it's a whole area where you want everything dead, you could smother.

It looks as if the area is a hard surface such as side walk or driveway. There are flame throwers that are sold as weeders. It can kill many other plants too.

Do you have a power washer? Set it to the highest temperature....
Have a go at it....

Nuclear?
(: