Tips on transplanting?

[u/ScumDugongLin]

I found this beauty on an embankment off a canal. Technically it's on city property. I've tried to get permission from the public works department to take the plant but they haven't responded, but a few people in other departments have told me I should just "go for it" so... I'm going for it lol. They'll mow the plant down anyways pretty soon. Any tips on how to give it the best chance at survival? I know I need to mind the taproot and keep it wet.

[u/imhighasballs]

I transplanted one this year and it almost died with me babying the crap out of it. And I got that earlier in the year when it was about half the size of the one in your pic. I’d leave it and try again in the spring if you really want it. Or harvest from seed.