I am bumping this thread. Anyone??

I have H. mutablis 'Rubrum' and have grown it for years. It looks to do fine in z7, so certainly worth a try in z6b, I'm not far from the zone delineation.

Well even if we're in the same zone, you're more south so it's warmer in general. What was the lowest temperature you ever got there? I figure heavy mulching can help but I heard that this shrub dies back to the ground in some 8b winters... The fact that an almost tropical zone like that even kills it to the ground scares me in growing this plant in zone 6b/7a

Well last year, we saw 1F three times. A good number of years back, we had a polar vortex event, where it went to -27F overnight, but with a 3 foot snow blanket.

The good (or bad) is that this zone is very unsettled and two years ago on Dec 12th (if I recall correctly), it was 80F, that night 20F.

A polar vortex of minus 27 degrees f....? Not Celsius?? I've heard of polar vortex going - 10 below what the hardiness zone of a certain area states but - 27 in zone 7 is just crazy. So the hibiscus mutabilis is technically hardy to zone 4 then. Even with a 3 ft snow on it, how could that hibiscus possibly have survived that?

I thought nj had the worst climate, guess I gotta go out more

As a general rule, we don't have frozen ground. Though I'm sure below the ice sheet that was under the snow pile, we had frozen ground at -27...that was an oddity and colder than I had ever seen in zone 6 or 7 in half a century.

I believe the hibiscus survived that...but I'm not sure, I could have rebought and replanted. That was like 2010 or so I think.

Your climate is crazy. Nothing I've ever heard of.. Our ground becomes completely frozen usually around mid-december until April. And we are in the same zone so winter temperatures should generally be similar so not sure why yours don't freeze and mine does. Also how big has your hibiscus ever gotten all these years you've grown it? Height and width?

Oh, I'd say about six foot, really no more than 4 feet wide, with a single years growth (freezes back), it doesn't branch (or not much), though this year 5 stalks were produced.

Yes, the climate here is crazy. It's truly unknown what weather next week will bring. Every month we usually have days in the 70s, but in late winter and early spring, it could also be near zero during the month. It just doesn't stay like that.

That's part of what makes gardening fun here...you never know what can tolerate the climate (for better or worse).

Sorry forgot to respond. I have several other threads going on at the same time. But ok that's not too big, glad it will fit in a small garden. Also does it have any pretty fall foliage? Any yellow or orange?

No, it turns ugly and brown at the first frost (or maybe a bit before).

As of about a week ago, mine browned out and the last flower was probably about two weeks ago. Often it goes till November, but this year some early cold nights.