Major excitement in the cold frame -Arum

Jim McKenney
Thu, 16 Feb 2012 14:58:50 PST
Aaron, I'm not sure how to answer this because your experience sounds a lot like the experience of a friend who lives only about fifteen miles south of here, on the other side of the Potomac River.  

But my experiences here make me very reluctant to recommend any of the winter green aroids (Ambrosina, Arisarum except proboscideum, Biarum, and Arum in general except Arum italicum) as plants for the open garden. I've been gardening on this site for fifty years, and my extremely conservative attitude about winter green aroids was shaped long ago by the really severe winters which were of regular occurrence then. It was not unknown for the temperature to stay below freezing day and night for three weeks or so. I'm pretty sure my friend mentioned above has been growing them only during recent years - we've had comparatively mild winters here for years.

I think this garden might also be a comparatively cold one. For instance, winter aconites here begin to bloom about two weeks later than some only about a mile west of here on the other (sunny) side of a ridge. 

You might be right when you question the factor of cold tenderness. Here mechanical damage during the winter is often an issue: the foliage gets so beaten up during alternating freezing and thawing and especially wind and ice that the plants, although they survive, become smaller year by year when grown in the open. And then the year comes when they're gone. 

When the time comes to evict the big guys from the protected cold frames where they grow now (these are set against the SSW side of the house and I doubt that it has ever frozen on the inside of those frames) , I might try them in cold frames out in the open. Frames out in the open would experience long periods of below freezing temperatures, but would have the advantage of providing protection from ice and wind. That will be a good test of their cold hardiness because it will eliminate the wind/ice factors. 

According to my lists (I have not actually counted bodies) the following are still duking it out in the cold frames:  AA. byzantinum, concinnatum, creticum, cyrenaicum, dioscoridis, elongatum, hygrophilum, orientale, pictum, purpureospathum,  rupicloa and sintenisii.   

I'm in the throes of redesigning my garden now, and the plans include lots of cold frames for housing winter green plants. That's where the big arums will go when the time comes. 

Jim McKenney

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