Mine pulled through a nasty winter that killed some of my other trees, and they’re doing very well right now. I’ll take a look next time I’m at the garden to see if there’s any pattern to the flowers. But what you’re saying would make sense. I have other fruiting plants that flower first around hotspots.

I took a look at my trees tonight, and they both seemed to flower mainly around the center of the tree, bit to the top. Nothing too special looking, I just had frost cloth and no auxiliary heating.

Nice planters, did you build them?

PacNorWreck, I'm near you, maybe just a tad bit colder (8a, but I really think most of Seattle is on the border between 8a and 8b), and have a little yuzu in the ground that was covered only by a plastic sheet. It suffered some very minor branch die-back at the extremities (probably just because it's so small) but is now vigorously leafing out. It's in a sunny location near a South-facing wall.

Best of luck with your trees! I think the heat-island effect of being in Seattle proper does help me out, as I'm able to keep a Yuzu quite happy in a container which should be much harder than growing one in the ground. I actually wonder whether the core neighborhoods of Seattle are trending towards zone 9a if they're not quite there already.

Olympia actually gets a bit more heat than Seattle. But temperatures dip a bit lower too.

It has to do with the moderating effect of the water, being so close to the sound. Overall pretty similar climate though.

I remember when I was in the PNW I never saw any citrus. I think they prefer a good hot punch in the summer to produce quality fruit. The long cold wet winters don’t help either. The occasional winter arctic sweep would kill the rest.

They are extremely uncommon, and when people talk about growing citrus they're usually talking about growing it in pots and bringing it indoors for half the year.

Citrus has a lot of trouble growing here because of the low temperatures for half the year. Even though the Winters are relatively mild, it's a very short growing season in terms of the temperatures citrus needs to grow.

However, I have read numerous anecdotal reports of people managing to grow cold-hardy citrus varieties in the ground, typically in a sunny spot against the South-facing wall of a house. These cold-hardy varieties aren't that common and many people do not even know these citrus types exist. They also don't tend to be the same level of eating quality as the varieties found in the supermarket, so that doesn't help (although a few of them that can survive here aren't that bad).

I did see the local nursery carrying 'Flying Dragon', although that's strictly an ornamental or for rootstock.

We do actually have a fair amount of heat in the Summer, almost comparable to Southern California, but it is for a much shorter length of time. People typically use their air conditioners for about 2 or 3 weeks out of the year, although about half the homes don't bother having air conditioners.