Personally I'd first start by patting yourself on the back. Here in Massachusetts I bring all of ours in and keep them in a cellar where the temps are around 55 degrees. They get a small taste of water about once every three weeks. I brought one out and have had it hanging in a sunroom where it's now putting out new growth and some buds. It all boils down to "growers choice". Do whatever you want. You got it to grow. I noticied your in New Mexico. Is your plant indoors or out? Google up Geranium care there are hundreds of sites that can give you more info than I. Have a blast and happy growing.

Oh, it is too cold here ( it is minus 5 degrees here today in Albuquerque.. record since 1990!) in winter to stay alive outdoors so I brought the geranium indoors & it is now blooming.. my first success with indoor geraniums! I just didn't know if they should/could be pruned back to keep them bushier or how big they would get. In Iowa my grandmother would hang them in a paper bag upsidedown x the basement rafters & replant them outdoors in spring again.

Your grandmother has the right idea for her locality..cold, northern Iowa. Us northern folks get the wrong idea about southern locales; New Mexico suggests warm weather when approaching January....in California January is the month they plant so naturally.....

You can keep your geranium going with the amount of sun you have as long as possible...but as soon as it wilts, cut it back to about 4", remove any old leaves and bloom, any weak or damaged stems or branches; re-plant in a fresh pot with fresh potting soil or potting mix. Put something in the pot between the soil and the drainage holes.
Put it in the best sunny window you can...south or west is best and water to drainage. No more water until the new leaves form, then water only as the plant needs it.
Do not fertilize until well along in foliage.
Normally, up north we bring our geraniums out by the Ides of March..(15th) and do the same thing. We suspect New Mexico will have better sun pretty soon.
Its all up to the sun....its still low but getting better every day. Turn the plant every day or so to ensure all parts get equal sun.
When you water, always water to drainage, then dump the excess in the saucer. Let it dry down somewhat between waterings. Within 2 weeks you will have a fresh measure of leaves and more each day. It will bloom later when the sun is better.

I guess then that geraniums are not to be kept as a long-lived houseplant without pruning & repotting frequently after flowering? I then should expect my pretty blooming plant to gradually die back in the house? Here most people buy the potted ones for the patio in summer but toss them away in the Fall; NO... I can't do that!! ha No wonder my house/yard is full of plants people have tossed or given up on!

I must go take another pic of my blooming geranium! Thanks everyone for your help.

Vieja, you know your own weather pattern, be guided by past experiences. You shouldn't need to cut it back if it is doing well. But if the plant is becoming lanky, poor flowering or is looking rather dismal, then you choose to cut it back as you see fit.
Cutting the plant back some will encourage new growth as much as the sun permits.
If you can wait until after April 1st, then the sun will surely be in a much better light to promote the growth you want.

I save all my geranium's 1 is 10 years old now. I put them in the basement under a flouresent shop lights, they grow like crazy and bloom thru out the winter. Water when needed.
You won't harm them buy cutting them back. I usuall leave about 10" from the ground level. Just in spring dont take them from the basement to sunshine you'll burn the leaves start out in the shade and slowly intoduce them to sun for the first week..

Good luck

the geranium has always been in a south facing window so gets LOTS of sun. The flowers have lasted over 2 months but now are drying up so I cut them off but now see some more flowers coming on the plant!! I will not put the pot outdoors in summer though as I want to keep it as a houseplant but may take some cuttings to grow in a whisky barrel on the patio.. Haven't had much luck with the ones I plant outdoors though in the past but am so happy with the one I finally got to grow indoors! Am glad to hear about your 10 yr. old one though so hope mine does as well!

I took long railing pots of geraniums. They bloomed all winter in my greenhouse. Last year I noticed that when I put them out, they stopped blooming and restarted in deep summer. I would like to slow down the bloom now so that when I put them out in April/May, they begin to bloom again. Any hints? should they be cut back now?