Colchicum in cold climates
Jane McGary (Fri, 27 Jul 2012 17:34:14 PDT)
Dell asked,
I have a lot of colchicums that thrive here in
Zone 6/7. Among them are cultivars of C.
autumnale as well as C. agrippinum, C. bivonae,
and C. speciosum. They are all listed as being
hardy in Zone 4 if the drainage is good. Mine
grow with the shoulders of the bulbs only 2-3
inches below the soil. If one wanted to grow
them in Zone 4Â or colder, would deeper planting
make them less vulnerable to the cold? Would they tolerate deeper planting?
I don't plant my colchicums very deep, but once I
rescued some C. x agrippinum (which turned out to
be a different clone from the one usually grown)
from an old Portland garden where they had become
buried as much as 18 inches (about 50 cm) deep by
repeated floods. They were thin and elongated,
but they were still flowering, and when I got
them into the garden they flourished.
Jane McGary
Portland, Oregon, USA