Round-up is one choice.
Mikey has a propane blow-torch that I bought him when we stopped using Round-up a few years ago. I have to supervise him, though, because he set fire to a rose bush.
Renee

My husband said we couldn't legally burn, but that's kind of what I was thinking to do! It's right in the front of our yard, how would you propose doing it discretely?

I sometimes use boiling water, from a tea kettle.

You can also use pickling vinegar (10%b acetic acid). I would consider putting down Preen to prevent weed seeds from sprouting as well.

Patty S.

I use boiling water from my tea kettle to kill the weeds in the seams in our driveway.

Another vote for boiling water.

I use boiling salt water on weeds that come up in cement cracks.

Lots of ideas here, thanks so much!

Once I get the weeds out, if I use Preen does it require yearly application or more frequent application?

Also I realized my thread title is not correct; the rocks are 1-2" in diameter, set between 12" pavers, and the area is the size of a driveway. It's such a mess...I used to be on top of pulling them out but it is pretty overwhelming.

a good cheap way to do it is cardboard or black plastic weighted down by rocks. I have also used a quantity of mulch or bark set there temporarily until the weeds were gone, then moved to areas under plants. If you have to walk over it constantly, I would choose duct taped cardboard pieces.

Good question, I'd have to Google Preen to see how often you need to apply. It has some residual, but can't tell you how long that is. Just be sure it doesn't get into a veggie bed where you're planting seeds :-) This seems like an excellent option for your area. That, along with the current weed abatement plan of some sort should help to keep it weed-free a lot longer for you.

Patty S.

Believe Preen has to be reapplied every 3 months, but that assumes summer rains, which don't happen in CA.

Using a small burner to fry weeds in a paved area wouldn't be prohibited as "burning" under your local regulations. Just be careful to be fire safe. Hitting the weeds with a weed whacker first would make using a burner easier and safer. Roundup would certainly work well.