Here's where Georgism gets clever: The initial Georgism says that land should be taxed up to the value of its land-rent. Some progressive people said, well, that means the landlord wouldn't make any money anyway, so the government should just take (expropriate) the land. George said, basically, no. Let the landlord decide if it's worth it for them to keep the freehold.
Then, there are varieties of Georgism that disagree about whether the government should be allowed to tell you anything at all about what to do with your property. Some say you should be able to do anything on it. Others say not.
When I bought my house, across from an elementary school, I knew I didn't have a right to drill oil on it, or to build a factory making solid rocket boosters and dumping perchlorates in the basement.
That's all written into the code governing the land before you buy it. The Georgist question is: If I'm paying 100% tax on this land's rent value, does that mean I get to despoil it any way I want? Or do some rules apply?
That's a separate and more nuanced question; the answer is probably that the same rules would apply as do now, but that doesn't equate with expropriation.