The robusta yes. It might be OK like that. The windmill palm, why not plant it in the ground in 6b 7a? Give it some xmas lights and a double layer of frost cloth and it should do fine. Just my opinion.

Jay

Are you sure those winter temps AVERAGE in the 30's? That sounds pretty cold. (Detached garages tend to be colder than attached.) I overwintered my robustas in a two-car (detached) garage that averaged 40-55 F. over course of winter (minimum 38F.). (Small, electric space heater helped a bit on very cold nights.) The top two rows are windows and it faces due south. If your garage actually averages temps in the 30's, I would expect some problems. It's not the occasional dip into the 30's that's the problem; it's the sustained cold. Expect leaf damage at the least if not total defoliation. Buds will probably make it--especially if you refrain from watering at these cold temperatures. If you
are interested in using your garage as locale for overwinter some of your palms (many people do), I would invest in a max./min thermometer to see what conditions in the garage are really like. The windmills will not have a problem either inside the garage or outside in the ground (especially if you give them some microclimate advantage/insulation etc).

I agree njoasis. I had spear pull on potted trachys on a window enclosed porch whenthe temps dipped below 30f. Plants that are potted and are not covered suffer at much higher temps than protected ones in the ground.

Just to be safe does anybody think that it would be a good idea to wrap the Robusta up with burlap and make a little structure around it lined with bubble wrap even though it will stay in the garage over winter? Just to keep it totally safe. I dought the garage temperature will drop below 20 degress, but I just want to be safe.

-Palmlover1

I would think that the concrete in your garage is going to be real cold. You will probaly need to provide some warmth
in zone 6-7. I would do what i could to keep it warm if it was me.