I find this very interesting. I am a novice at both gardening and the art of season extension. I had never even read the packaging on a solar panel until last summer so I am floundering with this technology - but it is so much fun. This is like tinker toys for adults! I have a small 6 x 8 palram polycarbonate greenhouse. It sits on a deck. I created a trough inside the greenhouse using 2 x 6's, a rubber liner and then topped it with leftover ceramic tiles that I had so that this square footage was still usable for plant placement. I then made myself a solar water heater with pop cans, paint, pvc, plastic, wood and which originally worked using thermosyphoning but I considered that too slow a movement so I added a small water fountain pumps run by a solar panel. It is direct connected - no sun, no heat, no movement. Sun out, the water circulates to heat up the trough. It is not a huge gain, but I don't pay for any energy to run this spring throughout the fall. I have bought a deep cell battery and have additional solar panels set up in preparation to store energy for after sundown use - not to operate the pump, but for lighting or to run an ozone generator from time to time. I did try to insulate some for the later fall season using Johnny seeds bubble stuff but there wasn't much use to this. I do have a natural gas heater but shut it down for February and most of March because my GH is too leaky and I see no reason to pay to heat the outdoors. I will take you advice and do a better job of sealing the GH this year. I am also building a cold frame and will be making bases for two small pre-fab cold frames. I plan to have these completed by the end of next week. Our ground is still frozen so I won't be able to properly prepare the area for these to fit over for maybe another few weeks. I am champing at the bit. Come on thaw! Thanks for sharing your ideas with us. I will be looking forward to your posts.

Not as familiar with A. glabrum but A. grandidentatum is basically a small, heat/drought tolerant version of Sugar Maple. Tolerates alkaline soil & is still about zone 4 hardy. There seems to be little evidence how well they do under a humid East/Midwest climate, but I'd imagine they're worth trying. There is a cultivar 'Highland Park' also that is supposedly a hybrid with "regular" Sugar Maple (Acer saccharum) that was developed in Ohio, which *should* suggest at least the hybrid, if not the "straight" A. grandidentatum, would do OK in the East or Midwest.

I'm going to give this a bump. Barb

Kirk, study please the Conifer Treasury of the USA & Canada 4.0 2015. The cover photos are taken by Nate Cassell of Denver, who discovered many Pinus ponderosa brooms around Colorado. We published together the Jerry Morris file years ago. Breeder's Hall - 50 - Jerry Morris Life Monument 2.0 USA Sorryfully the broom seedlings of Jerry are not descripted, an estimated 2000 plants. Best wishes: Zsolt conifertreasury.org