Five favorite yellow-flowered geophytes
Jane McGary (Thu, 22 Jan 2004 09:44:22 PST)
At 09:37 PM 1/21/2004 -0500, Jim McKenney wrote:
Here's what I'm about to try for Colchicum luteum and, should I be able to
acquire another one, Iris winogradowii: after the plants enter dormancy,
I'll give them a few weeks at prevailing temperatures and then try storing
them in the refrigerator for the rest of the summer. The refrigerator here
gets opened so many times a day that the temperature is probably in the low
40s F much of the time, if that.
Has anyone else out there tried this? I would like to try this with some
alpine Saxifraga, too. Maybe even experiment with pushing them into two
growth/dormancy cycles per calendar year.
No, what they actually would need is nearly dry storage at a temperature
near but perhaps not below freezing, through the WINTER, and in the summer,
sharp night cooling and low humidity with excellent air circulation. Day
temperatures could be warm. Such conditions are, I am told, provided in
hot, humid Japan at a botanic garden with refrigerated plunge benches and
climate controlled atmosphere. Unless you invest in a growth chamber, you
are unlikely to make true high alpines very happy in Washington, D.C.
However, some Saxifraga should survive there with careful attention to
watering and frequent spraying for fungus infection, which is, I believe,
their main problem in humid summers.
I have not succeeded with either I. winogradowii (had it about 5 years) or
Colchicum luteum (3 years maximum), but I try bulbs like this along with my
alpines, which are plunged in pots on my covered porch facing east or
north, watered very carefully winter and summer. However, summers here are
quite dry and at my elevation, night cooling is sharp indeed -- as much as
40 degrees F between day and night, even on the hottest summer days.
Jane McGary
Northwestern Oregon