Arctic Express
Jane McGary (Mon, 15 Jan 2007 17:12:03 PST)

We in Oregon are having the same Arctic Express as California, only more
so, of course. It hasn't been above freezing at my house for a week now,
and I don't expect a thaw for 2 more days. We had plenty of warning,
though, so I put in place my version of the kind of emergency protection
Robert Werra described.

I grow most of my bulbs in coldframes, and when temperatures below 25 F are
predicted, I lay precut sheets of microfoam insulation (sold here in big
rolls by nursery suppliers) directly on top of the plants, then close the
frames as far as possible (some have permanent vents). This has been
effective down to 17 F, with little damage observed except on two or three
apparently completely tender species. Before laying the foam this time, I
removed some pots of narcissus in full bloom and brought them into my
solarium, where I also brought all my seedling flats, germinated and not
germinated, and a few other potted plants that I thought would be susceptible.

Unlike Robert, I grow very few South African bulbs, many of which probably
would not survive even the normal winter cold in the frames. But I do have
a lot of coastal Mediterranean, South American, and North American species
that generally cope quite well. All my pots are plunged to the rim in
coarse sand, which adds protection from extremes of temperature as well as
being very helpful in maintaining constant moisture levels.

Those who live in milder climates with occasional hard frosts, like Robert,
might want to keep on hand collapsible frame foundations -- boards that can
be stacked when not needed, and bolted together quickly at need, then
filled with the pots and some insulating material such as bark mulch or
whatever is available in the area and reusable in the garden. The
blanket-and-tarp cover would be supported by the frame.

Jane McGary
Northwestern Oregon, USA