I keep the foliage on mine until spring. As long as you have it in a well draining site there should be no troubles overwintering it ;-)
CMK

My "Mrs. Bradshaw" geum has not bloomed yet. Did you wintersow your "Fireball" or buy it as a starter plant? My "Mrs. Bradshaw" seems to be slowing growing. I thought it was the only plant that I had wintersowed this winter that had not bloomed but I happened to remember about the Peach-leaf bellflower.

I bought it as a starter plant last year. I thought that if deadheaded it would rebloom, but it hasn't rebloomed yet at all. Bummer...

I started Geum 'Blazing Sunset' inside spring 2009. They did not bloom the first year but have bloomed well since. Cut back the last blooming stem yesterday. I deadhead the spent flowers on the stem and new ones appear further down. When they no longer appear I cut the stem all the way back. This helps lengthen the time of bloom but have not had any new stems for rebloom. Mine is located near the mailbox and gets limited watering.

I don't remember if I cut back in the fall but can't imagine that I don't after the plants have died back from frost. Since they are along the end of the driveway they are covered with snow all winter and into the spring as that pile is the among the last to melt.

{{gwi:194544}}

Other than trimming off some of the blooming stalks, I leave mine up all winter. Mine are in a raised bed & mulched with gravel.

mnwsgal--did you have to chill your geum seed in order for it to germinate? I purchased fresh seed in June and had 0 germination. I just took the pot out of the refrig last week and am sstill hoping for germination for my Blazing Sunset. Any advice appreciated.

I did not chill the seeds. My records indicate that I sowed three seeds on 4-9-09 and had germination of all three seeds on 4-20-09. All three plants are growing well in the same bed. They were commercial seeds marked 2008. None of the seeds that I winter sowed on the same day germinated.
Good luck.