Saving Geraniums Through Winter

Each spring I purchase geraniums to go in my planter made from a repurposed BBQ. By early summer, they are blooming in profusion. But come the first frost, they are nipped down. I've tried mulching them with newspaper and extra soil, but that alone didn't keep the roots alive through winter.

I'm not one to give up easily. I needed something more to keep the freezing air away and warm the plants on sunny days. I also needed to allow rain water to enter so the soil didn't dry out too much.

I thought of a greenhouse type structure.  What could I use?

I started by mulching the roots with crumpled newspaper. This provides pockets between the soil and the outside air.  Then I tied a piece of fairly thick plastic over the top.

I snipped a few holes to allow rain to dribble through, but not so many that all the warmed air would escape. It was good that I constructed my makeshift greenhouse when I did. That night was the first heavy frost.  You can see frozen moisture underneath.

This spring I removed the plastic and trimmed back the dead leaves and stems. One of the plants was brittle, but three had moisture in stems near the roots.  Two were even sprouting new leaves in the warm spring sunshine. I won't know for awhile if they will fully recover, but I say this is a qualified success in saving my geraniums.

Do you save geraniums over winter?  What strategies do you use? - Margy