the protected cold frame

Jim McKenney
Mon, 19 Jan 2009 12:10:46 PST
Those of you who have been following my posts for the last several years
know that I have frequently mentioned my “protected cold frame”. I have
several cold frames, but only one is called the protected cold frame. This
little cold frame has dome more to expand my horticultural horizons than
anything else in my recent gardening experience. I’ve been able to grow
plants in that cold frame which I once thought I would never be able to grow

This cold frame is now in its third winter.  The first two winters were
relatively mild zone 8 winters for the most part: there were few extended
periods of severe cold and the temperature only dipped into the zone 7 range
briefly. This left me with nagging doubts about the true effectiveness of
this frame. 

Last week we experienced some solid zone 7 winter conditions: for most of a
three day period the temperature did not rise above the freezing point, and
last Saturday morning the low temperature early in the morning was +3° F
(about -16° C). 

As the cold front began to move in I closed the frame and covered it with a
double ply tarp – and then crossed my fingers. It was with a genuine sense
of trepidation that I opened the cold frame for the first time three days
later on Sunday afternoon. The news was all good: other than some very minor
burn where some foliage touched the glass, everything looked fine.
Everything in this case includes such things as Amaryllis belladonna in full
leaf, Lachenalia in full leaf, tazetta daffodils about to bloom, Freesia,
Gladiolus, Sparaxis and  Babiana  in active growth, a full grown Cyclamen
persicum from the florist months ago (still in bloom) and dozens and dozens
of fascinating odds and ends. 

For those of you in similar climates who are not running a protected cold
frame, you don’t know what you are missing.  Jim McKenney
Montgomery County, Maryland, USA, 39.03871º North, 77.09829º West, USDA zone
My Virtual Maryland Garden
Webmaster Potomac Valley Chapter, NARGS 
Editor PVC Bulletin 
Webmaster Potomac Lily Society

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