More context.

Here they are, at the ends, towering over smaller Begonias I'm assuming were wax type.

Looks like Dragon Wings. Very good begonia for full sun as long as they are kept watered. These look a little stressed though or not fed during the growing season.

{{gwi:438059}}

Looks like Dragon Wings. Very good begonia for full sun as long as they are kept watered. These look a little stressed though or not fed during the growing season.

{{gwi:438059}}

How cold was it there last winter?

Where are my manners? Thanks for the replies!

Yes, these are perennial begonias. You might keep them in a pot and bring indoors if you get a hard freeze. Dragon Wing is a cross between a bedding begonia and a cane. The canes will usually survive winter here in zone 9, though they may die to the ground, they'll come back in the spring.

Thanks for the reply and info. I wonder where the cut-off is for these? Going by the term "dragon wing" I found several sources listing Z10 as their edge of hardiness, so not surprising they're coming back for you. Thinking they must have been planted this year where I saw them, at the northern edge of Z8. With that much brick though...

When I was at that wedding, I bent down to inspect a patch of these Begonias more closely, testing a cane for flexibility, and it snapped and slipped into a cup of water I was holding. It was the weirdest thing! I felt so bad for it, I brought it home.

Hcmdcole, forgot to ask, what is the pretty plant behind your Begonia?

The pretty bush behind the pot of Dragon Wings is Breynia disticha (Hawaiian Snow Bush)

Thanks! This is the 2nd time I've asked somebody about this plant from seeing their pics. Hope I see one for sale soon! Apparently I really like it.

purpleinopp, begonias are listed as usually perenniel in the Hortus Third. I've learned the hard way that most aren't cold hardy.

Yes, that's what I was asking, where the line is usually drawn for the pictured plant, if people thought these were planted from scratch this spring or if they've been overwintering there. "If they aren't perennialized there, someone planted thousands of these everywhere throughout the grounds."

It is possible they overwintered if it doesn't get too cold or stay cold for long periods of time. Dragon Wings are probably best treated as annuals though since you can get a six pack for $5 or so each spring.