Hi Alisa,

Certain ragweeds (Ambrosia) species can be tough to control because of their extensive underground root systems.  Others are annuals, and can be eliminated by ensuring that they do not set seed.

For either type, pulling them can be very effective, though you may need multiple rounds of pulling for the perennial species before their resources are exhausted.  Mowing/cutting before they set seed can help keep the population under control.

Herbicides are also an option, and many different products are labeled for the control of ragweeds.  Be sure to strictly follow the label instructions of any herbicide.

I hope this is helpful!

Cordially,

John