I finally figured it out.
This is the culprit! It's a male Ashe Juniper tree in my next door neighbor's yard. That golden hue is pollen cones. I never realized before that juniper pollen has a smell, but juniper is what the air smells like. That's what it must be. The rest of the tree is very fragrant: the wood, scales, berries, and bark. Makes sense the pollen would be too.
I love Ashe Juniper trees, but I might not feel the same way if I was allergic to them. Ashe Junipers are commonly known as "cedars" around here, even though they're in a completely different genus than true cedars and don't even look much like them (true cedars look much more like pine trees, with needles and cones, instead of scales and berries). Like most conifers, they're very fragrant. I love the smell of a campfire made with some Ashe juniper wood, and the branches make good smudge sticks.
I might also love them because they're such a hated tree, so they seem like underdogs. Besides the notorious allergy, they're also hated for "encroaching" on pastures (similarly to mesquite trees in some areas, another tree I like that a lot of people hate), and even depleting the Edward's Aquifer of water.
Personally, I think it's a bit unfair. Like other "encroaching" woody plants, I don't think it's fair to blame junipers for being able to survive in overgrazed, under-burned, and overall poorly managed pastures when grass cannot. (In other words, they're a symptom of that problem, not a cause.) I was always skeptical of the idea that junipers are especially "thirsty" plants that are sucking up all our water, and now there may be science backing me up on this. And while I feel sorry for people who are suffering from Cedar Fever right now, people are allergic to oaks and elms too. However, those trees just don't seem to draw the same kind of hatred that cedar does (I am allergic to something in the spring. I'm not sure what it is, but I'm afraid it might be oak).
According to my next door neighbor, the owner of this house hated cedar so much that he cut them all down in this yard. That explains why my yard only has oaks and elms and ash, while the yards surrounding us all have mature juniper trees in the mix. Seems pretty silly to chop down all the junipers in this yard when there are plenty right next door. It's not like pollen respects property lines. But maybe the desire for revenge against the evil cedar outweighed any logic in this case.
The peas are doing fine, but I haven't harvested any so far. I also might not get any before we move, though peas are less of a big deal to me than garlic.
I can keep the nightshades in pots until we move and then plant them at the new place.