Ok like seriously, half the people in this topic are insane. You guys need to lay off for a second and look at what you're criticising.
The stuff in Van Buren with Harold becoming a fruit farm was just as silly and imo doesn't really capture the Fallouty sort of humour and 50s-esque style that makes Fallout what it is..
The developers always noted that "Bob" (the tree in harold's head) would continue to grow and eventually sprout fruit and was unusually resistant to radiation so to me the same thing happens in Fallout 3 as it does in Van Buren, really. Fruit drops off and causes other trees to grow- SHOCK HORROR! Thats what fruit is for! Whether Harold becomes an orchard or an oasis makes no difference to me really.. except the whole orchard thing, well.. harold being overwhelmed by the tree thats grown in his head seems like a pretty horrible, sudden, and ironic way for somebody's life in the wasteland to end. An inevitable death for somebody who would inevitably die, where widespread death is itself common and overwhelming.