We plan on being in the Portland area on June 5, 2018. Are we too late for spring blossoming rhodendrums?

You can see spring blossoming of rhodendrums by then.

No, they'll still be blooming, just not as many

I was there last week (May 21) and some of them had started dropping but most were still in bloom. It will probably be 50/50 by early June.

I don't know you might want to call they were in pretty full on bloom when we were there in early may, but who knows?

It's a beautiful place and the azaleas are probably still blooming. Might be some rhododendrons. But the best time is the last week of April or the first week of May.

There should still be plenty of blooms

There should still be rhodedendrons blooming at that time. There are also flowers besides rhodedendrons at the garden. It's a lovely spot, I'd recommend going

For sure and they are beautiful