Do you know what kind of weed this is, and how to eradicate it? It's not possible to pull it out from the root, and they are sharp and thorny. They grow quickly and spread rapidly. I've avoided spraying herbicides since I don't want to impact the soil and future plantings; but I also haven't planted anything new because I'm scared it will be a waste if it's just taken over by these weeds. I live in DC suburbs in Maryland.
Would it be OK to just spray Roundup on the entire bed, let them wither and die, and then start from scratch? I've heard varying information on how Roundup affects the soil.