<>Crosseyed Mary: they are awful to eradicate! Best to cut them to ground level which is tedious. Weed killers will do it but they are resistant. I had five that I cut to the ground, then tried herbicides. They started to return so on advice from a friend I poured petrol on them, let it soak in, lit it then to make sure a few days later poured more petrol on them but didn't light it. That worked. The white parts covering your plants are the seeds too. Best of luck !Crosseyed Mary: they are awful to eradicate! Best to cut them to ground level which is tedious. Weed killers will do it but they are resistant. I had five that I cut to the ground, then tried herbicides. They started to return so on advice from a friend I poured petrol on them, let it soak in, lit it then to make sure a few days later poured more petrol on them but didn't light it. That worked. The white parts covering your plants are the seeds too. Best of luck !