reptileguy112 wrote:I will have to consider getting a hoe.I think it would use way to much vinegar to not be cost effective.I would prefer something to definitely kill any plants.
A hoe is a little tough to use in rocks unless they're small, like pea gravel, because then you can push the rocks around to drag the weeds out of the soil. I've never had any success with the big taproot stuff we get here in the desert though. When you start getting into larger rocks, stones, boulders, river rock stuff, the hoe is a lot of work and not that effective, at least in my experience. So in our rock garden, we weed by hand. Big stuff first, then plucking here and there whenever we're out there to keep it manageable, then right after the last spring rain, we bite the bullet and spend several hours pulling every weed by hand. Wet ground makes easy plucking. If it's green, and I didn't put it there, it goes. Then we starve them. The plants in the garden get targeted drip and nothing else gets a drop of water. We didn't put plastic or any barrier down either. The spring rain brings some weeds, we get rid of them, then it's free sailing until the following year. If nothing else is supposed to grow there, then you can make an afternoon of it, pull them all from the root (a large flat blade screwdriver is a handy tool for dislodging taproots). The suggestion to smother with cardboard until they all die is also something that would definitely kill all (or at least most) plants.
Then, cap any irrigation that keeps giving the seeds a chance to germinate. If it rains, pluck early at the first sight of any green.
Your other solution that will definitely kill any plants is a chemical one. It can be short term, or long term, but if these rocks are uphill from, or in the vicinity of, your garden, the chemicals will likely leach into the soil below your raised beds and kill all plants there. A spray that will kill a weed, will also kill a tomato plant.
The answer you seek isn't the answer you want.... but pulling the plants out by hand, in what sounds like a relatively small area, isn't as bad as it sounds. We weed a 300sf rock garden exposed to desert winds that blow in off a field in a couple of hours. That's mostly all gnarly aggressive taproot type weeds and little teeny tiny creeper groundcover plantlets that are everywhere! Cilantro would be a walk in the park. And you could make chutney!
Good luck, and enjoy your 13 trees!