O. fragrans is not completely hardy in zone 7a. And would often burn in winter sun. I think you would be disappointed with its performance 2 to 3 out of 5 years.

Not quite the same fragrance and certainly more spiny, but you might consider the hardier Osmanthus x fortunei. Would make a good hedge. Blooms for a few weeks in the fall with very fragrant, but otherwise insignificant flowers.

Agree w/Dave, Orange County is going to be too cold for straight Osmanthus fragrans, but its hybrid offspring O. X fortunei will be fine...and is very fragrant too.

Is it true that when they reach great age, O. X fortunei lose their spines?

O. fragrans appears to be generally unsuited to local winters even in my part of USDA 8, with growing late into fall, resulting loss of most recent growth flushes some winters being seen.

The Seattle arboretum does have an old, small (as in a few individuals) planting on a greasy clay bank that is supposed to be this species (and looks the part), seems to have been hardy. But it could be some kind of special wild collection* from a higher altitude or otherwise different in this respect (climate adaptation) from what has been on the market here.

And maybe pretty much everywhere else in the US.

Some species of shrubs are represented in cultivation primarily by tender forms that do not reflect the full range of the species. A prominent example is Camellia reticulata, with specimens of the typical wild plants having lived in Seattle plantings for decades. Whereas the old Chinese cultivars of that species brought back to the West from temple plantings turned out to be strictly for soft winter areas.

Maybe there is a similar situation with the osmanthus.

*Either I haven't thought to look this accession up in their planting records or I did and nothing illuminating was encountered

davidrt28: yes, mine are losing spines toward the top. But apparently with (some/most?) Osmanthus, when you root the top portion of an older plant, they begin to grow spines on the new leaves again. Go figure.