Back when I would save geraniums over winter, I tried to take tip cuttings by mid August before the overnight temps were consistently falling below 10C (read somewhere that the lower evening temps change the cellular structure and lower the chances of rooting). Then in a sunny warm window thru the winter so they'd grow. Prune back depending upon size of plant, pinching once in mid February when the days start getting sunnier and longer, and then again mid April.

My mom keeps the original root ball and stems, and stakes hers. They do look lanky on the bottom, but it is amazing how many cluster/bloom heads those plants will put out! One has to be 4 feet in height (and staked and kept out of the wind). She will get some branching lower down, but it doesn't appear to be too strong, but then again, she doesn't prune them back very hard (like I would). During the winter, she keeps them on the dry side in a window in the garage where the temp never gets below freezing, so I think she is holding them over in a dormant state.

I used to save mine overwinter when we lived in the city. I would take up the plant, trim the root ball and the top and repot in clean soil and leave them in the garage where it was kept just above freezing. I would water only a few times during winter, just enough to keep them from drying out completely. I did not use lights as I did not want the geraniums growing. I forgot to mention, water them before bringing them in using an insecticidal soap mix to kill any insect eggs, also spray the outside of the pots, you never know where those kritters lay eggs.

I used to not have a place cool enough to store them, so had to keep them inside...of course, then they got leggy, and I hated to cut them back in the spring when they got blooms. Now I have a refrigerator in the garage just for pelargonium, fuchsia, and dahlia tubers. If you have the space, you can usually find an old one for free.

Our garage is actually DH's workshop. It's minimally heated all winter, but there's definitely no room for plants in it. As for a fridge - good idea but you have to pay for the hydro! LOL I have way too many to keep in a fridge, anyway. :) But thanks!