Question
QUESTION: I have a nice bunch of Perennial Hibiscus that I raised from seed. At this point they are potted and outdoors and about 3 to 6 inches tall. My question is how do I Winter these over (I live in Connecticut).  

Should I put them in our deck room maintained at 50 degrees all Winter and maintain watering. Or should I bring them in, withhold water and let them go dormant. Or
should I plant them in the ground, where they will certainly freeze, and Winter them over that way?
Thank you, Art

ANSWER: Hi Art,
Thanx for your question.  Are we talking about tropical or hardy hibiscus.  The hardy hibiscus are Hibiscus moscheutos and it is cold hardy in your climate.  I believe it's rated down to zone 5.  You can set them out now after placing them in the shade for about 10 days to help the get accustomed to the outdoors.  They will need full sun.  If you're talking about tropical hibiscus, these are the ones that usually have the long gold stamens and their leaves are somewhat shiny?  You can overwinter those in your deckroom but I'm thinking 50 is probably a bit too cool.  I wouldn't go lower than 60.  I have put mine in the patio doorway and they get pretty raggedy in the winter but snap out of it pretty fast once you place them outdoors again after the last frost.  I hope this helps.  
Tom

---------- FOLLOW-UP ----------

QUESTION: Hello Tom,

The young plants I now have are the hardy hibiscus and they have already been hardened off outside. I take it from your response, that I should put them in the ground and let nature take its course this Winter. Is that correct? I'm just a bit skeptical about leaving these tender little plants in the ground for the Winter here in CT. (I can only plant them at a depth of 2 to 3 inches at most due to their small size. The will certainly FREEZE solid during the Winter.) As an alternative, is it possible to keep these growing (or let them go dormant) in our deckroom thru the Winter. Having raised them to this point, I don't want to KILL them ;-)

We also have a Tropical Hibiscus and it winters over just fine in that deck room held at 50-55 Degrees F and has done so for many years.

ThanX, Art

Answer
Hi Art,
I know that it may seem hard to believe but hardy hibiscus are very, very hardy.  I've seen them survive -15 F here in the Kansas City area when we had extreme cold spells over the years.  If you put your seedlings out now and keep them watered and fed (I would feed half strength fish emulsion.) they will be very strong and will survive the freezing winter.  You can also mulch them with some cedar or cypress bark.  If you plant them now, you will be surprised how quickly they will grow before you first frost depending upon your location in Connecticut should be sometime between the 15th and 31st of October.  The SE Coastal area can even be later some years as you probably know.  You may winter them over if you prefer in you deck room.  As far as your tropicals go, when I make recommendations to others, I am usually somewhat conservative with my temperature estimates. If what you do is tried and true, I would stick with it.  I keep all of my tropicals in the basement which is not heated but stays around 60 degrees during the winter.  Pretty much everything goes dormant or semi-dormant and on occasion I'll lose something but it's usually something that has already been weakend or wasn't doing well to begin with.  I hope this helps.
Tom