Colchicum luteum

Jane McGary janemcgary@earthlink.net
Thu, 22 Jan 2004 10:03:40 PST
Thanks to John Grimshaw for his helpful comments on Colchicum luteum. I 
purchased a bulb of it from Janis Ruksans last fall and it is now in bud -- 
I should have cold-stored it as John suggested. Too late now, but I'll give 
it extra attention with fungicide.

Early crocuses are also susceptible to Botrytis if the spent flowers are 
left on them in humid conditions. You can easily remove the dead petals 
without disturbing the ovary, and still get seed. Unlike many UK growers, I 
have never had a problem with Botrytis in the Fritillarias I grow, except 
for some that came from China via Paul Christian, obviously already 
infected; I am now trying to grow the Chinese species from seed as it 
becomes available from growers who are handier with the spray bottle.

John also mentioned the spring-flowering Colchicum kesselringii (the tiny 
one that looks like a white-and-purple crocus) as needing similar treatment 
to C. luteum, but I haven't found this necessary. C. kesselringii has grown 
and flowered here in the bulb frames for 12 years, blooming in March. I dry 
it off in summer.

Colchicum luteum grew well in one garden in Portland, that of Margaret and 
Howard Mason, in what appeared to be an ordinary well-drained border; 
however, the Masons also succeeded wonderfully with Nomocharis, Himalayan 
lilies, and Asiatic gentians, all of which challenge most gardeners in this 
region. I suspect part of the success with the Colchicum depends on getting 
just the right clone, since it is so widespread, as John mentioned.

Jane McGary
Northwestern Oregon, USA


At 07:07 AM 1/22/2004 +0000, you wrote:
>Jim McKenney is suggesting putting Colchicum luteum into the refrigerator
>after it has gone dormant. While I would never stop anyone experimenting,
>one needs to think how these plants grow in the wild. As I understand it, C.
>luteum has a huge distribution in Central Asia eastwards to Kashmir: all
>areas that have a long hot summmer quickly followed by cold winters. The
>Colchicums, I believe, emerge as the ground melts and do their thing quickly
>before the summer heat comes on. The point is, however, that a long hot
>summer is experienced, and I suspect that this is necessary to the plant's
>physiology to trigger the initiation of new buds etc. It may well be
>disrupted if the bulbs receive too long a chilling, especially at the wrong
>time of year.
>
>In the UK C. luteum has a reputation for being difficult to grow, and being
>a martyr to botrytis. What happens is that they are planted in autumn and
>watered like other bulbs. We have no cold weather worth mentioning (these
>days especially) and the poor things come into flower in December, elongated
>in the low light so they look quite terrible. Then the flower fades and
>flops onto the foliage, and promptly develops botrytis, encouraged by the
>high atmospheric humidity. This spreads into the foliage and in no very long
>time, the plant is dead. To get round this I leave my pots of C. luteum and
>C. kesselringii (another C Asian species) dry from the time the plants go
>dormant until January, and repot them then. I did it just last Friday, 16
>Jan, this year. The bulbs have a fringe of embryonic roots and the shoot is
>well developed, so as soon as they are watered (as they would be with snow
>melt in the wild) they develop rapidly and will be in flower within the next
>few days. The growth remains compact and the plants grow with increasing
>daylength and warmth. Botrytis remains a problem, but is much less so than
>earlier in the winter. I have been growing C. luteum from Kashmir since 1989
>and from Tadjikistan since 1991 (also C. kesselringii) so these 'difficult'
>species can be maintained for a reasonable length of time. The biggest
>problem with this method is to keep the plants growing long enough to build
>up a decent new corm; a touch of dryness in about April will send them
>promptly to dormancy. This obviously happened with mine last year, as they
>are smaller than I really would like to see, but they're now back under my
>eye.
>
>What I would suggest is that the bulbs could be potted in autumn and allowed
>to make some root growth, but are then put into cold storage until the
>spring or late winter. But it would have to be cold, 1-2 deg C; any warmer
>and they will grow!
>
>John Grimshaw
>
>
>Dr John M. Grimshaw
>Gardens Cottage
>Colesbourne
>Nr Cheltenham
>Gloucestershire GL53 9NP
>
>Website: http://www.colesbournegardens.org.uk/
>
>----- Original Message -----
>From: "Jim McKenney" <jimmckenney@starpower.net>
>To: "Pacific Bulb Society" <pbs@lists.ibiblio.org>
>Sent: Thursday, January 22, 2004 2:37 AM
>Subject: Re: [pbs] Five favorite yellow-flowered geophytes
>
>
> >
> > 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.
> >
>
>
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