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

More information about the pbs mailing list