Try 1 gallon vinegar mixed with 1/4 cup dishwashing detergent and 1/4 rubbing alcohol. You can also add some salt but if you plan on planting there the salt is not a good idea. This spring I "wiped out" a whole patch of poison ivy using this formula.

I only have 3 or 4 of them. Do I pour all the 1 gallon? Or should I use my sprayer?

So it's poison ivy?

It's not poison ivy.

You have Field Bindweed, frequently called morning glory, related but different from what you grow in the flower bed. It is a perennial, has an extensive root system, and is hard to kill. Roundup is the right track. Just keep spraying every bit of growth that appears, or set a small dish of high strength roundup on the ground and set the vines through it so they can really soak it up.

You can also lay cardboard down on the ground where it is coming up and leave it there for a year. Mainly, you have to kill the roots to get rid of it, so it takes repeated herbicide applications or other measures to prevent it from getting light until the roots die.