Dividing fall blooming bulbs

Rodger Whitlock totototo@telus.net
Sat, 01 Oct 2011 16:44:56 PDT
Normally, you don't think of dividing bulbs when they are in growth. The root 
disturbance involved could be expected to set the plants back.

However, at least two genera of mostly fall-blooming bulbs can be divided with 
complete success as they come into flower: colchicum and sternbergia.

It's long been my practice to lift, divide, and immediately replant overcrowded 
colchicums just when they come into flower: they're easy to find then, and 
their roots are only a fraction of an inch long, thus not disturbed 

Within just the last few years, I've found that the same is true of 
sternbergias. A very few bulbs of (probably) S. lutea 'Angustifolia' rescued 
from a badly overgrown site at the back of a neglected border were lifted and 
translated to a sunny raised bed. I've lifted and divided them in the fall at 
least twice now, and have 30-35 bulbs with 20+ flowers this year.

Sternbergia lutea, in an ordinary garden centre form, was purchased last year 
and planted nearby. Last week I subjected it to the same process of lifting, 
dividing, and replanting. While the philosophers are unanimous in saying we 
should not count our chickens before they hatch, nor our sternbergias until 
established, to all appearances it appears that this group has also survived 
this treatment with no setback.

The advantage to lifting and dividing is that it gives the individual offsets 
plenty of elbow room underground, with the result that they grow more strongly 
than if not divided.

Another fall bloomer best lifted and replanted now (but not divided) is that 
old reliable Cyclamen hederifolium. Judging from the occasional mutilated tuber 
I have unearthed over the years, I suspect you could even chop the tubers in 
two and both pieces would re-establish. Dusting the raw surface with sulphur 
would be advisable to prevent rotting.

Rodger Whitlock
Victoria, British Columbia, Canada

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