Thanks again. Come to think of it I think there's a pink variety somewhere in the garden.

Since a "weed" is a plant you do not want growing where you do not want it, only you can determine if what you have is a "weed". The white flowers, near as I can tell from the picture might be a member of the Daisy family which does not necessarily eliminate from the "weed" category. The larger looks similar to a plant I have that sometimes has a common name of "gooseneck" something that I need to dig deep into the memory bank to find.

I began digging a small lone one out to hear a thick root snap. From what I saw, it has a thick tap root for the plant's small size.

Here is how really specifically: Go to Your Houzz in the upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone. If you add info on your state or the nearest large city you will get even better information since zone only relates to average coldest winter temperatures. Then return to the top of the page and click Done Editing.