I've always coveted glass garden cloches but could never find any other than expensive Victorian antiques. While browsing an arts and craft catalog, I saw these small glass lampshades for just a couple dollars each, and I ordered a dozen.
What do you think of wintersowing, IN SITU, under these lampshades? What problems might I encounter? I wonder if they will get too hot on sunny days. I don't want to have to fuss over them too much.
Might work OK. It's hard to guess how much heat it might hold. What zone are you in? Maybe 7 or 8? It might be best to only have it on for your coldest months. But then your seeds would be unprotected. I really can't relate to winter weather that far south.
How big is your lampshade? Big enough to not be blown away? How big is the hole in top?
---We are in zone 6 or 6B. The garden is in Asheville proper and so the altitude is somewhat less than 3000 feet.
---Each lampshade weighs 6.25 ounces, which is fairly heavy for their size. The glass is 3/8 inch thick, the base outer diameter is 3.75 inch and the top opening is almost 1.25 inch across.
--Today our temp was in the mid 60s, full sunshine and no wind. After 3 hours of afternoon sun I put my finger into the one cloche I have put out so far; it's the one in the photo and it's over a forget-me-not seedling. It seemed only mildly warm inside the cloche. The seedling showed no evidence of heat stress, but the soil was very moist and that could have attenuated the effect.
I'm shocked that you could be in zone 6? Are you certain about that?
I guess they might work OK as long as they don't fry. Of course you could have a lot of thinning and/or transplanting to do if it works well. Seems easier to me to just sow in jugs and transplant but that's just me. Are you planning to do any in jugs, or just direct and under the glass for everything?
I have done plastic jugs, cut-off water bottles, etc. at my other house, which is secluded. Here in town I feel the plastic stuff looks messy and ugly. Also, I am searching for an in situ method of winter sowing.
If you look at a hardiness zone map you will see a narrow band of zone 6 or 6B oriented with the Appalachian mountains which extends NE to SW through western NC. Maybe all maps don't show it. In fact, this region is littered with microclimes. One can find niches which run the gamut from zone 5 to zone 7 or even 8, depending on the altitude and protection afforded by ridges, hollows, large boulders, etc.
Ooneek, I found your question very interesting and it caused me to google "cold frame" gardening (in a wood and glass frame directly over the soil) because that seemed to be close to your idea of WS under glass cloches. I learned that early in the history of the WinterSowing site, Trudi advocated winter-sowing in a cold frame, and then later she focused on making use of various containers, generally recycled plastic milk or water jug/containers.
That doesn't mean that you couldn't use your individual glass cloches. I do worry about heat build-up because glass concentrates heat more than thin plastic does. Also, I'm not sure about what the alternate freezing and thawing would do to the glass--maybe it's tempered?
For me the individual plastic containers work because I can more them around easily for watering when Spring arrives--eventually I always remove the tops entirely. Also, I generally winter-sow "thickly" because I don't know how many seeds will germinate and survive, and the larger size of my jugs/containers accommodates lots of seeds.
Having said all this, I think you should try using the little glass lampshades and tell us how they work!