Hoe or pull before they get that big, certainly before they flower & set seed.

Do they bleed white sap when you break a stem or leaf?

Yeah they bleed white sap. Can't hoe them cause they are mixed in with the grass. I've pulled them but the come back within a couple days

I have one flower bed where these keep popping up. I am trying to figure out what they are also. I see them no where else in my yard or surrounding area. My son loves giving me wildflower mixes and this bed is the one I always put them in so didn't know if it was something in the mix from previous years.

I believe they are some kind of Lactuca. But the id is not really relevant. They just need to be pulled out, with help from a fork or trowel if necessary.

If you are talking about the tall weeds, which I assumed the OP was, they are not Lactuca, but I think after looking at pics online it is milkweed.

I am not familiar with milkweeds since they don't grow here so you may well be right. I asked about the sap with Lactuca in mind but presumably Milkweeds are called milkweeds for a reason. Would milkweed be 'all over' a yard? Are they that common and prolific?

My first thought was milkweed, also. Even though they're not native to your area, a good number of people have been planting them, as they are Monarch butterfly host plants. They reseed like crazy!

Like I said I have them coming up in one bed and after looking online, I am going to let a few of them flower and see what I think. I love butterflies :) I am in Virginia and don't know if they are native here.

Another thought, would they be included in a wildflower seed packet, since this is the bed, I toss those in when my wonderful son buys them for me. LOL