Dollar Weed invading my garden!

I have been living near Myrtle Beach, South Carolina for 3 years, and I'm still learning about the native plants here.  In previous years, I've been able to keep the dollar weed from taking over my garden, my I'm losing the battle this year.  It spreads by deep, underground runners.  I don't want to use chemicals in my garden but did try horticultural vinegar which knocked it back only temporarily.  At this point I'm using a pitch fork to lift it out of the soil, but it's a very time and energy intensive process.  I tried cutting the leaves off, but it just sends out more leaves the next day! If I leave it alone, it would take over the garden.  Any suggestions?  

Carolyn  

I am not familiar with that particular weed, but generally speaking if manually pulling is not enough, there are three routes I might suggest.

Find an animal that will eat it, and put them in a pen over that area for a while

Use a "natural" herbicide like vinegar. This is effective, but I found out it can effect amphibians negatively, so use with care.

Plant something that is more vigerous than Dollar Weed. Mint, Diakon radish, buckwheat perhaps.

Good luck. Having a plant take over is no fun.

**Edit - I completely missed that you had already tried horticultural vinegar. I imagine it is much like boiling water, in that, you may need to apply multiple times to kill a large plant, or one with deep/extensive roots.

Since you said that horticultural vinegar was only a temporary relief, I would suggest trying boiling water.

The boiling water might kill other plants that it comes in contact with.

Then I feel when mulch is applied very thick the mulch will suffocate the dollar weed.

I would suggest 6" to 12 " to start with.

I have read that dollar weed is caused by excess moisture so I would also suggest not watering those areas where dollar weed is at.

Thanks for the suggestions.  I'll try boiling water, but some of the runners are more than 6 inches deep, and the water may not penetrate.   However, it might kill the leaves if I'm persistent with it.  

I've not tried mulch that deep, but I'll give it a try.  I have tried cardboard with mulch on top, but the runners happily run under the cardboard and out the other side!  

I know dollar weed thrives in wet areas.  I live in Coastal South Carolina where it is always humid and wet, so there isn't much I can do about that.  

I'm going to use horticultural vinegar around the perimeter of my garden to deter the dollar weed from creeping into the garden in the first place.  

I used to have Mexican petunia that had runners that ran under my patio.

With persistence, I got rid of that plant so it can be done.

It seems to me if you can keep the leaves cut back or killed with boiling water or vinegar then the roots will finally die from lack of sunlight, especially the ones that are 6" down.

That is why a thick layer of mulch works.

As the dollar weed dies then move the mulch to another spot.