Pat, keep your Geraniums in a cool to cold room. Nowhere near heat.
My MIL had a Geranium for years. It sat in an unheated hallway, in a small east-facing window. Her Geranium was huge, healthy and bloomed year round.
Its trunk was at least 4" diameter.

Her home was heated by space heaters. One day she decided to set her Geranium in the LR. A big mistake. A few months later, it was loaded with Mealy Bug.
It managed to survive, but God only knows how since there were 50 times more bugs than leaves. lol.

I've rooted Geranium cuttings in cold areas..they did fine, grew into large plants.

They need sun, too, of course, so place your Geranium in the brightest window possible. Artificial light helps. A standard light bulb is better than no light at all.

If your Geranium is growing spindly, pinch back a bit. If you feel comfortable cutting it to the soil line, do so, but if you're Geranium's healthy and compact, there's no need to cut it down.

Water like you would a succulent, especially in winter. In fact, treat it like a succulent, and it will do well.
Bright light, cool rooms, and let soil dry between waterings. No fertilizer is needed unless sun is shining, but reduce by 1/4 dossage. An All Purpose fertilizer is fine.

Late Feb, early March, you should see new growth. If days are sunny, up the fertilizer to 1/2. If it's rootbound, repot in a larger container, but only if needed. When temps permit, place it back outside, and fertilize with the amount you normally give during summer months.

Geraniums are one of a few plants that go outside in early spring. If it's outdoors early enough, it will adapt to sun, but if temps are too cold, 'under 45F,' it will have to acclimate to bright sun. That's about it. Toni

Toni, thank you so much. I always look for your advise on the forums, so this is great.
I'mgoing to have to move it to the basement to get the coolness it needs. I remember as a kid reading Thalasa Carouso's book about geraniums. She was in England and they hang their geraniums upside down (no soil) in their dirt basements to winter-over. I never wanted to go to that extent,but I will put it in our basement and hope our south window will suffice. I also remember now that in the spring this year I had actually planned to move it to the basement and put it under a plant lite. Wonder why I forgot about that. Old age is so wonderful.
Thank you so much again.
Pat

Thank you so much too Toni!

You have certainly helped me to decide what to do with my 6 plants! I was debating what to do all this time an now you have made it easier for me.

With your success, now I am confident I can carry them through the winter. They smell like citrus and have a powerful fragrance, especially when it's cool out.

Mike

I was reading up on this lately! I get the impression that a lot of Pelargonium species are more or less deciduous anyway.I have no idea to what extent this carries over to the hybrids you see in cultivation though.

Pat, I've heard from people who hang Geraniums in the basement..no soil/upsidedown. I tried it once.. They died. lol.

Whatever, don't make the mistake I did. Two summers ago, I decided to unpot all my Geraniums and plant in the garden. Oh, they did great outside. Problem is, some grew way too large. Others froze. I feel like crying when I think how stupid that was.

Here's one of the Geraniums that went in the garden. BTW, it was 4-yrs-old.

{{gwi:110304}}

Mike, what type do you have?

Amccour...it depends on the type. I'm still confused about zonal vs seedling Geraniums. Is one a tender perrenial?

The Pelargoniums that are grown for their trunks can be deciduous. It depends on light and cooler temps. If placed in low light and a hot room, leaves drop. Otherwise, they'll remain, but grow very very slow. 'winter.' Toni