For those of you who are regulars of long standing on this list, what follows is water long under the bridge. But since there seems to be renewed interest in cold frames, I’ll repeat here some of what I’ve said in the past. Keep in mind where I am: east coast Maryland where winter sun is bright and temperatures can drop to about 0º F (about -17 º C). In other words, this is not sunny California. For me, the main advantages of cold frames have been these: - they allow me to grow many winter-flowering plants which are impossible in the open garden - they allow me to control moisture - they provide a great place to winter marginally hardy plants - their economy is very appealing However, there is one huge disadvantage to cold frames in our climate: they require attention at least twice a day in the matter of opening and closing them. A couple of hours of January sunshine will cook the contents of a cold frame exposed to the sun (and for most purposes you definitely want the frame to have a sunny exposure). I have not tried the automatic openers recommended by some people. There is no evidence that the temperature inside my most protected cold frame has ever dropped below the freezing point. For instance, Zephyranthes grandiflora has gone through the winter in full leaf and never showed any sign of freeze damage. This year I’m trialing some Paphiopedilum and Kalanchoë – so far, so good. I cover the glass light with a double ply poly tarp whenever the outside temperature is below freezing. If the daytime temperatures are predicted to be above freezing, I take off the tarp and prop up the lights a bit to allow ventilation. If I have to be away for a few days, the tarp remains in place until I return. This has turned out to be a good place to grow marginally hardy aroids such as Biarum, Ambrosina, Arisarum and Arum along with a big range of other plants which produce active foliage during the winter. I’ve successfully flowered one of the Chilean Tropaeolum in this frame, and Nerine sarniensis has been in this frame since 2005 – although it grows well it is erratic about blooming. Give cold frames a try – you’ll probably be surprised with what you can get away with. But don’t blame me if your successes in a cold frame soon have you tearing up the yard and spending big bucks to install a greenhouse to house your rapidly expanding collections. You can see my first cold frame here: http://jimmckenney.com/a_protected_cold_frame.htm Jim McKenney jimmckenney@jimmckenney.com Montgomery County, Maryland, USA, 39.03871º North, 77.09829º West, USDA zone 7 My Virtual Maryland Garden http://www.jimmckenney.com/ BLOG! http://mcwort.blogspot.com/ Webmaster Potomac Valley Chapter, NARGS Editor PVC Bulletin http://www.pvcnargs.org/ Webmaster Potomac Lily Society http://www.potomaclilysociety.org/