Medieval/Viking Age Greenhouses?

[Ireth]

What sort of greenhouses might there have been in the 800-1200 AD period? I know the practise of making greenhouses dates back to the ancient Romans; one emperor in particular, Tiberius, had greenhouses built so he could have cucumbers every day. Those greenhouses were made of mica rather than glass. "Modern" greenhouses date back to about the 16th century or so. So far, though, I haven't found any information on the centuries between.

On the other hand, should I give myself some wiggle room on the basis that the novel I'm asking for is a fantasy that takes place in Faerie, not real-world Earth? The Fae would certainly have their own ways of keeping fruits and vegetables from shriveling in the cold, but those methods wouldn't be available to the human protagonists. I do have a few elemental mages who might be able to create glass for greenhouses, or I could just have another mage enchant a certain area so that it stays at a spring/summer temperature even in the dead of winter. They'd need the greenhouses for food plants, medicinal herbs and the like, as well as probably a place to just escape the cold for awhile. XD

 

[CupofJoe]

Sorry don't know much about greenhouses [apart for a prohibition on throwing stones] but does this help...
Fleece and straw have and are used to protect low crops from frost. The fleece would have been carded and stretched [but not actually woven] in to a fairly thin blanket. The straw might be thrown over very low plants or bundled in to fascines or faggots and stood around bushes. And I can just about remember muslin cloths wrapped around Hops on their wire trellises to stop the wind and frost getting to the new growths. It really was like a scene from the 19C watching the men unwrap the bushes...
None of these would stop a deep prolonged freeze but they would and will stop heavy frosts.

 

[Devor]

You won't find anything about Norse greenhouses. We just don't know enough, and big panes of glass screaming "greenhouse" wouldn't have been available to the Norse. Also, Norse soil was fertile, and the summer seasons are terrific, so they didn't really struggle with food the way we might assume that they did.

I've asked about greenhouses before, here.

The best you might do, short of magic, is a small farm you can put a tent over in the cold or at night. Light a fire under the tent, boil some water to make it humid, then pull it all down at dawn so the plants get sunlight.

 

[Ireth]

Thanks to you both for the feedback. As I said in the original post, though, the story is set in Faerie. The place I'm thinking about having the greenhouses is a magically-warded castle, where the wibbly-wobbly-timey-wimey nature of Faerie doesn't have effect on the mortals living there. That basically means they age normally rather than remaining stuck as they are the day they entered Faerie, and eventually becoming part-Fae themselves. The seasons still pass normally, but the flow of time is still very different from Earth. The weather in Faerie is supposed to be similar to what you'd see in real-world Scotland, Ireland or Wales, not Scandinavia. There is also no true sunlight; everything that grows in Faerie is sustained by the magic that makes up the entirety of that world, including the warded castle area.

The mortals who live there occasionally make excursions to Earth to get things they need, like lumber and stone for building, rather than harming the trees of the forest and royally pissing off the Fae. They do have gardens and the like when it's warm, but sometimes it's better to have fresh herbs for medical emergencies in winter rather than dried ones. These mortals are a somewhat diverse group originating in various parts of Scandinavia and the British Isles: the main group of humans are Norse-Gaels whose ancestors came to Scotland and Ireland on Viking ships, but who settled among the Celts and Gaels and adopted their culture somewhat while still keeping ties to their heritage as well. They have Scandinavian names, and still sometimes swear by and pray to the Norse deities alongside the Celtic ones.

 

[Devor]

They do have gardens and the like when it's warm, but sometimes it's better to have fresh herbs for medical emergencies in winter rather than dried ones.

Herbs don't really take a lot of space and time to grow, and you've got faerie magic to boot. You might be over-researching what you need. You just need a steady cycle of light, heat, nutrients, and water. Shouldn't be too hard.

 

[Ophiucha]

Yeah, magic is definitely the easiest way to get around this, but in the interest of research...

I know that in Korea (around the medieval period), two things they used were wetted blankets to help regulate the humidity and underfloor heating, an example of which has a convenient diagram over on Wikipedia. They need sunlight, and methods of that varied. Some people seemed to just wheel the plants out for an hour or two every day to get a bit of sunlight, while others had high ceilings with windows to let it in without letting the room get too cold - they did have glass, so certainly there could be a bit of it, if necessary, just not an entire structure like we have today. Building them underground was another good way to help regulate the temperature, though it did make the sunlight part even more of an issue. You could always try to strike a balance of some of these with magic for the things that are too inconvenient (for instance, heated floors and a good flow of moisture could be done naturally, with the sunlight handled by the fae).