The hardy hibiscus (usually H. moschetos) don't grow as "trees". They are more herbacious in that they don't really form a permanent woody "trunk" that resprouts in spring.

The type of hibiscus that forms a tree that is hardy in colder areas is the commonly known "Rose of Sharon" (H. syriacus). So you can look for that if you want something that can keep a "trunk" that will resprout in late spring/early summer and give hibiscus blooms.

I think there's lots of confusion about that "hardy hibiscus" moniker that going around in the plant trade nowdays. It seems that rose of sharons , which are related to tropical hibiscus and in the same "mallow" family were called Athea for many years, but recently are called Hibiscus , so there's much more confusing the "hardy" Rose of Sharons, with the tropical hibiscuses. with some growers confusing the names even more by calling the rose of sharons , hardy hibiscus now. I guess , unless you can pin the growers down to say, what they're actually selling, that problem will remain. Sometimes the whole question of hardiness is even more confused , when sub-tropical growers talk about "hardy" plants, when they by no means mean "cold hardy". Some plants will tollerate windy conditions , hot locations , and some drought and for the sub-tropics , those are hardy traits that don't fall into the same category as "cold hardiness".

Hi,

I have seen the hardy hibiscus "trained as trees" at Jackson and Perkins

Just bought 24" braided trees for around $8 each at Home Depot central Illinois....hope they don't die this winter!

I have a hardy hibiscus tree about 8 feet tall with dinner plate sized flowers. Last year's growth is quite lignified and I wonder if it would have sprouted from the same place had I not used a hacksaw to cut down the growth last december.