Yellow somewhat tender Lyroris

Jim McKenney
Tue, 10 Sep 2013 18:36:18 PDT

I'll be glad to do that, Nick. 

First of all, to get a general idea of what I did, take a look here:

That should give you a good idea of what I did - as you can see, nothing expensive or fancy. 

I've had many unexpected successes in this simple frame, and I attribute most of them to the siting of the frame: it's against a house wall facing SSW. Apparently it either never freezes within this frame or many plants which I think of as tender actually take some freezing. During extremely cold periods I've seen frost on the inside of the glass, but I've never seen signs of frost or freezing on the plants themselves (unless the leaves touch the glass). 

I like to tell people that simple cold frames like this one are a lot like dogs: they pretty much take care of themselves, but they definitely need attention at least two times a day. The glass is propped open daily, even in freezing weather (just a tiny bit) and on mild days (much more). NEVER allow sun to strike a closed cold frame. If you have to be away during the day, cover the frame with an opaque tarp or something similar. Even in the dead of winter, sunlight striking the closed frame will quickly send the temperature soaring, enough to kill some plants outright and to damage the foliage of those not killed. 

At  the end of the day the glass is let down. If the weather is severe, after the glass is put down the entire frame is covered with a two-ply plastic tarp. Because the frame is sited against the house, it gets whatever heat seeps from the house foundation. I suspect that this is a significant factor in the success I've had. In really severe weather (those periods when the day time temperature does not get above freezing and the night time temperature hovers down into the single digits F, I'll leave the frames covered with the tarps for days at a time. 

For the summer, the glass is opened from the back side (i.e. the side against the house wall): this, and the fact that the frame is in the rain shadow of the house, keeps out rain. Some of the plants are grown in pots, others are rooted in the ground. 

I have two of these frames - they are managed a bit differently since one contains mostly summer dormant plants, the other contains tender plants which are summer active. 

I've frankly been amazed at what I can get away with with these frames. I've been able to grow and flower plants here which in the past I would have said were impossible in our climate. The frames are a daily bother, but it's worth it. The only regret I have is that there are only two frames, and they total only eighteen square feet each.  Curiously, I've never had a desire for a greenhouse. But when I'm out working with my frames I'm as happy as can be. 

I have not tried the automatic frame openers. 

Email me privately if you have more questions - or post them to the list if you think others might be interested. 

Durham isn't that much different than Montgomery County, MD, so you should be able to repeat my successes and no doubt add more of your own.  

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