in my experience with tea olive, the fragrance can be strong at times, depending on weather conditions. when mine flowers (fall and winter here), if i am near it in the early mornings or at night when it is cool and perhaps damp from dew, i can not detect a fragrance. however, as the air warms and especially on dry autumn days with high air pressure, it will waft a long distance from the shrub, smelling just like apricots to me. also notice the same scenario with nicotiana and even petunias. check the box store garden centers in your area. they stock them here (i want to say about $6.00 for a 2' tall plant)and they should be blooming now.

I have two that are hanging on...I adore the scent, hubby can't smell them at all. Mine are very scrubby looking. Last fall I was in New Orleans walking thru the French Quarter with a friend. We started smelling a glorious scent which I thought was tea olive. We rounded a corner and there was a stand of about 8 tea olives in tree form, about 10 feet high and loaded with blossoms. Shopkeepers were standing out on their stoops to enjoy the fragrance. Nothing like it.

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

You hit the nail on the head -- a new build. Builders use marl and fill dirt to build up lots, and only add about 6 inches or less of topsoil. Your soil is the problem. This is what I would do, because you are going to have to do this for everything you plant until you get some organic matter into the soil. Adding organic matter will attract earthworms, and they'll eventually break up that bad soil. Get some good bagged topsoil and composted manure and mix them together well. Cut the plants back by 1/3 to account for them losing roots when you dig them up. No need to remove diseased leaves, because they will die and fall off on their own. Dig up the plants and wash the leaves and roots well in soapy water, rinse them well. Dig a hole 3x the diameter of the root ball & six inches deeper. Fill the hole with water. let it soak in, repeat. Put six inches of the good soil in the bottom of the hole and place the plant in the hole. Add soil slowly until the root ball is level with the top of the hole. Fill with water again, and as it soaks in, add soil to fill the hole to the top. Poke all around the hole with the handle of the shovel to fill in air pockets. Build a dam about 3 inches high around the plant out to the edge of the hole with the soil you dug out of the hole and fill it three times with water and let it soak in. (I realize this sounds like a lot of water, but most of it is going to soak into the marl or fill dirt around the plant) Water every other day for a week, every third day for two weeks, then once a week for two weeks unless you get an inch of rain, always filling the dam three times. You may have to keep rebuilding the dam. I wouldn't fertilize or put any more insecticide on them until you see new growth in the spring. Good luck!