The Wikipedia entry is more informative than the article you point to.
However, the entry is wrong in dismissing the story about the druids cutting mistletoe with a golden sickle. That is taken from Pliny’s Natural History (XVI/95): “A priest arrayed in white vestments climbs the tree and with a golden sickle cuts down the mistletoe, which is caught in a white cloak.”
However, Roman information about druids, etc., is not reliable, and Pliny might have been basing his ideas on Aeneas’ golden bough. I don’t think mistletoe ever grows on oaks, as Pliny states – !’ve only ever known it grow on trees in the rose family (apple, whitebeam, hawthorn, pear, etc.).
The Norse myth about Balder is fascinating, linking ideas about love and sex (Frigya), Yule, and vulnerability. The Christian folktale about Christ having been crucified on mistletoe wood doesn’t make sense, and I suspect that it was transferred from Baldr, as Baldr is a sort of Apollo/Christ figure. I vaguely remember stories from childhood about magic arrows made from mistletoe – I don’t know whether they were genuine traditions based on the Balder story. There is a River Balder, named after the god, in County Durham, and I have always wondered why it was so named.
I think a lot of the mythology is due to mistletoe being strange, shooting out odd-looking, glossy leaves from a tree of a different type. The Yule significance of holly is mainly because it is the only native, broadleaved, evergreen tree in the British Isles and Scandinavia (there are now so many non-native trees in parks and gardens, that we don’t realise how striking holly must have looked 500 years ago). Mistletoe is also evergreen, and that must have added to its importance.
In some apple-growing ares, especially Hereforshire, mistletoe cultivation is an important sideline for farmers.
As a child, I was always told that mistletoe doesn’t grow north of Birmingham, but I recently found some growing on ornamental trees in a park in Yorkshire.
You might be interested in Richard Mabey’s book, “Flora Britannica”, although it might be difficult to find in the USA.

Out here in Sonoma County, California the mistletoe grows mostly on oaks.

I’ve seen mistletoe growing from oak as well.
The author’s assertion that “Cursing other plants to die in winter, his mother, Frigga, queen of the gods, decreed that mistletoe would be a symbol of love and peace from then on. Baldr was resurrected each year at Jul” is pretty strange to me. I’m very familiar with the Prose Edda (the primary source for the story of Baldr’s death by mistletoe), and I just looked up the story in one of the translations to make sure, and there’s nothing even remotely like that in there. It’s also definitely not in the Poetic Eddas or Saxo’s Danish Histories. I think he may’ve gotten hold of some very late folk tradition (or something even later, perhaps something Rydberg-influenced?).
I don’t particularly want to register at HuffPost Social News to ask him his source, but maybe I will.

I think the thing about mistletoe as a sign of peace is a Scandinavian tradition, rather than something out of the classic myths.
I don’t think the thing about Balder being resurrected each year at Yule has any basis anywhere. I suspect that it’s just made up to resemble other dying-and-rising-god myths. Anyway, why would it be at Yule, not in spring?
Does anyone else think that the story about Christ being crucified on mistletoe wood was transferred from the myth about Balder being killed with a mistletoe arrow?
About growing on oaks, the American mistletoe (Phoradendron serotinum) is a different species, indeed different genus, from the northern European one (Viscum album). In Britain and Scandinavia there is just one species, but in Italy there are several, and Pliny may have been thinking of a different species. Frankly, I would take Pliny’s description of the druids with a pinch of salt.

The webpage at http://www.thepoisongarden.co.uk/atoz/viscum_album.htm states that the European mistletoe, Viscum album, does grow on oak in rare instances although it prefers to grow on softer wood. There is even a photo which to my untrained eye looks like mistletoe growing among oak leaves.x

Mistletoe definetly grows on oaks as my trees will attest!