I have a recipe I use for killing poison ivy, wonder if it would work just as well for you and be cheaper in the long run?

1 cup salt, 1 gallon vinegar, 8 drops liquid detergent.

I think you can probably eliminate the detergent from the recipe.

Thanks, sparrowhawk, but I'm afraid that this would kill my roses as well as the grass that's creeping into the center of them :) I can dig out the grass around the outside but I have a hedge that is monstrous and has thorns like you would not believe! I can reach the center with the long wand on my sprayer, but digging it out is beyond me, since I don't own a suit of armor LOL!

Here is a link that might be useful: Outer rose hedge

Well, I had no idea - wish I had a hedge like that when I had problems with neighborhood kids!

I've never seen this product so I had to do a little checking. Ortho made it, but it is no longer listed on their website. Possibly it is a product they no longer make, but there are still a couple of retailers online that are selling it. What's in the stuff anyway?

I'd be tempted just to mulch heavily under those roses. Straw and good ole compost. If you really loved them, you'd treat them to some cow poo ;)