Wintering over tropical Hibiscus

I have a braided, multi-colored, tropical Hibiscus that I'd like to keep, if I can. I have an 8'x12' greenhouse [1], that will be heated [2] as an option, as well as bringing it into the house. I'm wondering which would actually be the better place to winter it. Indoors would definately provide a more stable environment. I don't have forced-air heating, so the air isn't much drier in the house than outdoors, but winters here can be pretty dry [3].

This is my first go at a Hibiscus, and it's a really nicely done display. If I lose it, I'll write it off as a learning experience. It's not really a big deal, but I'd like to know others' in the area have luck in keeping them, and which would be a better place to do so.

[1]. Rion GH46

[2]. The greenhouse is still being finished, but the heaters I've purchased will provide a total of 5400BTU, which should be plenty to keep plants from experiencing abiotic stress. However, as I've not had the greenhouse through a winter yet, as a reference, I'm leery to shove all of my warm-loving plants into the greenhouse and cross my fingers.

[3]. I have a fairly large capacity humidifier, if needed.

Thanks,
Eggs

Eggs, what is the glazing on your Rion GH46? With this information, we should be able to calculate the temp you will be able to maintain.

My experience is that tropical hibiscus overwinters (and continues to flower) easily except for one thing...whiteflies. They are whitefly magnets. Two years ago, I battled and battled all winter, then finally in disgust in February I through the stupid plant outside.

This year I will try again, with a new whitefly weapon...imidacloprid. This is a systemic that lasts for months, commonly available as "Bayer Advanced Tree and Shrub Insect Control Concentrate." Two tablespoons per gallon, water thoroughly. I have had great success with this product on ornamentals in the GH. I do not use it on edibles.

You won't need a humidfier in the winter, that is my experience.

SB

The glazing is double-wall poly that is, IIRC, 4mm.

I had planned on using a systemic insecticide on a lot of the things that I was going to put in the greenhouse for the winter. I hadn't decided on which flavor of poison, yet. I appreciate your insight.

The humidifier would be if needed "in-house" only. The greenhouse will have humidity controls. =)

Thanks for the reply,
Eggs

Eggs - Good question. A friend has a few that he wants me to overwinter in my basement under lights. I'm going to try it, they are so beautiful - I hate to let them die.

I overwinter two of mine...I prune them down about 1/3 then keep them in a south window...I have a humidifier in the same room with them...They do great!! Put them out in LATE May and by july they are blooming!!!

Eggs......I have an 8x12 greenhouse I constructed myself....this will be the 3rd. year. I keep all my tender plants in it, along with potted, named daylilies that I will trade through the winter and at spring swaps. I have never had a problem with any kind of insect, but I spray everything, once a week with insecticidal soap. I've never tryed the Bayer Concentrate but may try some of it in conjunction with the soap. I keep hibiscus, bromeliads, cactus, and several other tenders and have never lost anything. I think the secret to the greenhouse is to keep the air moving. Good luck.....Jay

Moonlighter,

Sorry for the late reply. Busy season at work, right now. Thanks for sharing your experience. I opted for the greenhouse a couple weeks ago, and so far everything is doing so much better than I'd hoped. Got down to the mid 20's the other night, and with only one heater running (I have two), it was about 55F when I left for work at 0430.

Rather than spray, I've opted for a systemic insecticide. Sprays in enclosed areas aren't my favorite thing to experience. =)

Now, if I can just find the time to get the rest of the weatherstripping in. So many windows....
*sigh*

Hi....As an aside, most of the family is in your area this weekend sampling the grapes! We weren't able to make it because of the bean harvest. We finished Friday, but had to spend about a day moving equipment around etc, so was too late to go.

I filled my greenhouse Wednesday ........right before the Wed, Thurs, and Friday nite freezes. I used a small electric heater both nites and it never got below 55. I have a 10,000 BTU propane wall furnace, but won't use it till the temp stays cold for a few days and the elec. heater can't keep up.

Hope you're enjoying the fall colors. They're just starting here......nice to hear from you..Jay

Somewhere I read that Hibiscus don't tolerate systemic insecticides. I bought a bottle, already to use it, till I read that. I will see if I can find where I read it.

Crystal

crystalnurse,

I treated all of my greenhouse plants with the systemic, and none have shown any ill-effects. As a matter of fact, most if not all of the plants are absolutely thriving. I've not seen an insect anywhere inside the greenhouse, and I'm pretty thorough in my inspections. Were what you had read true, I would think there would be a lot more info, with regards to problems. I've seen/read/heard nothing, and my boss suggested it's use. I say, "go for it". =)

Heck, I'll try it on a few and see. I've already got those nasty gnats flying around and I just got everything moved in. How I wish I had a greenhouse.

Crystal

I use systematic on mine also... Crystal, you might try mosquito dunks (shaped like a donut) in your water. I break them in half or fourths (depending on the size of my watering can). Let it soak in the water and add more when they dissolve away. When you water the "stuff" from the dunks is supposed to kill the gnat larva that are in the potting medium....

AuntB - have you used the dunks on the hibiscus and they tolerated okay? I've got a couple down stairs - so I am off to soak it. Thanks

Crystal

we use dunks at our house and it hasn't hurt anything....cept the skeeters. And we have to be careful what we put in the ponds around our house and everything cause the dogs like to swim in that water too.... They've all been just fine. And it hasn't harmed plant life either.

This is my second year over wintering Hibiscus in my Rion GH. They do get pretty messy with all the leaves turning yellow and falling off. My Hibiscus last winter didn't have very many leaves on them but they sure bloomed all winter, they really looked a little funny with the flowers and no leaves. I didn't have any problems with white flies but I did use scanmask on all my plants. I didn't use a humidifier at all last year. Every morning the GH had a lot of compensation in it which I figured was enough moisture.

I have a Black & Decker little heater that I use, set it on the frost setting and I know there were a few nights that it got down to about 37* and my plants did all right. I know they say Hibiscus don't like to be down below 40*'s so maybe when it got down to 37* it didn't stay very long. I do know one thing I never lost anything in my gh last year.

I put mine in the basement with the brugs, etc... I know it occasionally gets below 50 but not freezing down there. There is a small south window for some light. Sometimes they lose all the leaves, but once they sense spring is on the way, they start showing new green. I have lost a couple but it's better than putting up with the bugs growing them in my upstairs living area (and space is limited). Although, I do have 5 up there right now (youngins'). I'm thinking of chopping them back before Christmas and moving them down then. I guess the basement challenge is to keep them alive (not totally dormant) but not actively growing with just enough water to live and not promote root rot. That is my strategy. I would love to have a nice big greenhouse.

I keep Hibiscus, Bouganvillas, Bromeliads, and other tenders in my greenhouse, and I keep the thermostat on 36. It's a small gh, so it's easy to regulate the heat, and I use two 9" oscillating fans on all the time, in addition to the fan on the propane heater. I have never lost an established plant. I did start 14 cuttings of Brugs about two months ago and have lost two of them, but not to weather. I figure if I can come out with 12 out of 14 I'll be doing ok. As I said in this thread, I have only used insecticidal soap sprayed on from a hand sprayer once a week and have no problem with little critters or flying insects. If I ever do, I will certainly try some of the products mentioned above. And AuntB, you will think you died and went to heaven when you get a greenhouse. I spend a lot of winter hours just sitting surrounded by green and blooms. Sure takes the Winter doldrums away.....Happy gardening!

Jay In wet and cool NW Missouri......

Jay when I read your post that referred to Bouganvillas as "tender" I couldn't help but laugh. When I lived in Tempe I had a large Bouganvilla that went up a trellis in the front of my moble home. I never did anything with it during the year and I'm sure because of living in the city in the desert it was certainly warm enough. Can't say that I specially watered it either. I didn't like that it had big nasty thorns since I had toddlers around the house and eventually got rid of it. However, it was pretty growing up the front of the house!

About 2 years ago my DIL and I went into Houston to a neat nursery, and they had Bouganvillas everywhere and they were so pretty. I thought I had to have one until I noticed the thorns. No way did I want one of those. Then the saleman told me in my zone I would have to bring it inside in the winter, and that made up my mind more then ever. But they are pretty. This is another reason why I don't want roses, is because of the thorns.

I can tell ya it was pretty rough getting that all taken out of there that's for sure.....

Hi all. Let me stick my nose in here, OK?
I've had tropical Hibiscus for 30 years. In the house for the winter and out for summer. I use a 'fruit tree' spray on them before bringing them in. I hose them down after the spray dries, shake the drops off and drag them into the basement to dry. Then up to the living room. Occasionally a spider survives but nothing else. It doesn't hurt the plant either.
I've lived in a few homes with the Hibiscus, one only had north facing windows. They did OK but had few flowers there.
I've also had a Bugainvillia for about 15 years, in a pot hanging under a skylight. It's almost a Bonsai because of the tight conditions but it blooms plenty. It never goes out.
Andy P

I bought a tropical hibiscus for $2.00 last winter when we were visiting relatives in Florida. Brought it home on the plane and tried to keep it alive inside until it was warm enough outside. I had it in a clay pot, and when I took it outside, I sunk it into the ground, pot and all. It thrived, but didn't bloom until late summer. When the weather got cool a few weeks ago, it stopped blooming and I brought it in, and put it in my basement, where I have grow lights. It was on the floor, a good four feet away from the lights. A couple of days ago, I noticed it had tons of flower buds on it, so I brought it upstairs and it's in a south window. Yesterday morning, I walked in the room and found this. By this evening, another bud had opened and there are at least a dozen more coming on.

I'm a happy girl! Wish I knew which cultivar it is, though. The nursery where I bought it didn't know for sure.

Kylee

Oh Kylee, how beautiful! Someone will know what it is...I have some blooming in a south window, too. I want to cut them back and store in the basement, but I just can't bring myself to do it. They aren't real bushy and are about 3-4ft tall.

I just counted, and there are 16 new flower buds forming on it, in addition to the two that are blooming right now (well, the first bloom is twisting closed). There is no way I'm cutting that thing back! I want to see the show! I just don't know if I should fertilize it now or not. I know when I had it inside last winter, after I brought it home from Florida, I had a heck of a time with it losing leaves. But when I got it outside in the spring, it came out of that in a week or so.

Logee's sells these as house plants, so I'm guessing they do okay inside all year round, if you have to do that.

KB, I prune mine in the Spring when it goes out. Like you, I want the color in the house when I need it, lol.
Andy P

Exactly, Andy! And that is why I ordered a bunch of new amaryllis for the winter, too. LOL

I love the color inside this time of year, also... but about January, I'll probably be infested with spider mite, I HATE that, so I'm trying to thwart the infestation. I've got baby brugmansia (plus other stuff) growing in the other south windows.... maybe I'll just put Christmas lights on them call them the tree (ha). (The kid's would have a FIT)!

The only thing I've ever had a spider mite problem with is some ivy that I bought this past winter. That plant was in our bedroom, not near anything else, so when I noticed the problem, that one immediately went outside and I sprayed it well. Got it under control, but I just left it outside anyway.