Hibiscus is a rather large genus found worldwide and includes shrubs,
perennials and annual species. Some of the Chinese shrub species, such as
Hibiscus syriacus, are cold hardy but the majority of the shrubby species
and their hybrids are strictly tropical. The perennial species in the
Hibiscus moscheutos group of the eastern US and their hybrids are also cold
hardy. There are also a number of annual species that are seldom seen in
gardens.


"Ted" wrote in message
ups.com...
A couple weeks ago, I found at Home Depot, and bought, what they called
a "Rose of Sharon". It didn't look like any rose I've ever seen.
Instead its flowers looked like small, about 6 or 7 cm across (or about
2.5 inches), hibiscus flowers. Their horticulturalist said it is
winter hardy here (just a two hour highway drive north of Toronto
Ontario Canada), but that it tends to be a bit tender here.
(suggestions on protecting it, if in fact it is hardy here, would be
appreciated)

Today, I saw some plants, labelled as hibiscus at a grocery, and the
card that came with the plants from the store's suppliers says it is
hardy to USDA zone 5 (which I think includes us here). I thought
hibiscus were strictly tropical, and that the "rose of Sharon" I bought
might be a temperate cousin (smaller, hibiscus-like flowers on shrubby
stems). But the "hibiscus" I saw today looked to be as large and
colourful as those tropicals I'd seen at real garden centres, but on
stems that seemed as delicate as the stems of my begonias, with no
trace of wood. The card from the supplier said it would die down over
winter and start new growth in May, and then bloom until first frost.
While the flowers were as large as the tropical hibiscus I'd seen, they
didn't seem to have as much substance (a more papery look), but I don't
know if that is damage from the excessive heat we've had this summer.
My irises and lilies gave a less than adequate display this year
because of the heat. The card with them also said they'd stay small,
two thirds of a metre to a metre tall at most.

Anyway, is there really a hibiscus species or hybrid that is winter
hardy in a cool temperate region with such delicate stems? Or are these
plants certain to die like annuals here?

Can anyone shed light on this?

Thanks,

Ted