More to explore:
wilipini underground greenhouse in zone 4b, going to grow citrus
Sugar snap peas in January, zone 4, unheated greenhouse.
Zone 4, unheated greenhouse, January lettuce.
Simple Ideas That Are Borderline Genius – 32 Pics
Greenhouse full of rosemary topiary.
the whole website is greenhouses from recycled doors and windows ....lots of ideas
Growing Garlic/Best advice ever on garlic growing
Tips on growing peonies