Colchicum

[Lesley Cox]

Thanks Mark, so that's what you look like.  I guess I have to post an image of my self now.

Arnold
New Jersey

 Yes Arnold, go for it. The long and the short and the tall, as the song says, likewise the cute, cuddly and downright plump. We have no secrets here. And a warm welcome to the Forum of course, from the deep south.

[anita]

Hi,
Although this thread hasn't been active for a while didn't want to start a new thread.
I've been reading that colchicums are tough to germinate. As a novice I'd bought some Colchicum bivonae seed from Marcus Harvey in 2009 and sowed it at the same time as Crocus seed. While the various Croci? came up thickly I had a solitary Colchicum seedling come up last year and reading the forum I wasn't sure I'd do any better this year. But I read the paper Arnold posted to the forum and wondered if the seeds were used to getting baked on their native mountain sides before shooting in spring. So last summer I put my little terracotta pot out in the summer sun to bake - as we get days of 40 C here during summer, those little seeds were truly toasted. This year we've had pretty substantial (by South Australian standards rains) and when I was checking the pot a fortnight ago I spotted the first signs of little shoots. There are now 22 little seedlings on their way up! I'm not sure that I had many more seeds than that in the pot. Anyway I thought I'd share the concept. I'll try it again with seeds sown this year... I'll plant in spring and bake through summer and see what happens next spring. Cheers Anita

[Maggi Young]

Your experiment with the seeds has been a real success , Anita, congratulations.
Good to know there are some advantages to living with that level of heat.
  
I'd try the same but getting 40 degress here in N.E. Scotland pretty much requires a sun lamp!  

[ArnoldT]

Anita:

Great news, the theory is that when the seeds are produced they are not yet fully ripe.  They ripen during the hot months and then germinate the following spring during the wet season.  The authors found a higher germination with warm and dark conditions than anyother treatment.  Of course it all makes sense after the fact.

[Darren]

This is valuable confirmation Anita - thank you for posting your experience.

I had hoped to experiment using a 30C incubator this year but access to it was difficult. Instead I've been looking at propagators with adjustable temperature so I can try this in future.

[Pauli]

Hello!

A C bivoniae from the Olympos area!

All the best from Austria

Herbert

[anita]

I'm going to do a controlled trial of colchicum + summer heat this year. I've bought a number of different species from Marcus Harvey and I'll try planting some now (mid-Spring Southern Hemisphere) and the remainder in autumn. The seeds sown now will be left out to bake through summer and I'll compare germination rates of the two batches in a couple of years - hopefully!!
Anita

[anita]

My colchicum trial is underway. The seed was planted in December to see how a hot summer would affect germination. As nature would have it we've had a relatively cool summer with just a single heatwave to date. Anyway during January's mini heatwave I took some soil temperatures...these seeds are in terracotta 21cm pots, covered by gravel and sitting in the sun. I took the soil temperature on Jan 29 at 1500 when the exterior temp was 42C and the soil temperature rated at 45C. I took the temperature again at 1900 (still daylight) and it was 35C. Next morning it was 20C at 0900 and 45C at 1730. On the morning of the 31st it was 29C at 0635 hours, again late afternoon the temp was again 45C. It'll be interesting to see if I get any germination this autumn! Anita

[Darren]

Thank you for the update Anita. I think we would struggle to replicate those soil temperatures in the UK - even in a good summer! This should be a really good test of the theory and I hope to hear reports of abundant germination in a few months from now!

[Gene Mirro]

Need more heat?  Use a bigger light bulb.  Or control the light bulb with a light dimmer.  To keep the potting mix moist, place the pots inside a plastic bag and seal.

Note that you don't have to build anything.  Just use nursery flats and bands.

Disclaimer:  if you are a complete klutz, please do not build this thing.  You can electrocute yourself or burn your house down.  I would die of guilt.

[Darren]

I've gone for the low-tech approach.

My colchicum seed (plus seed of the South African Ornithoglossum undulatum which is related and did not germinate last year - it is still intact) has been sown into small black pots, kept just moist and placed in the warmest place next to the glass in the greenhouse. The pots get quite hot to the touch during the day and cold at night. This should duplicate fairly well the conditions in late summer experienced by the Ornithoglossum at least. in a month or so when the nights get colder I will put them outside with the others.

[Ezeiza]

Anita, to make the trial complete you need to store the same kinds of seeds under room temperatures.

In my experience, Colchicum seed will germinate through several years and most important is not to dump the pot with seeds if no results are visible. Right now, seeds of Colchicum lusitanum from a Portugal Botanic Garden have been germinating after years of being sown.

What Arnold says about immature seed makes all the sense.

[anita]

Update on Colchicum baking trial.

Some of the colchicum seeds I planted as part of my “baking trial” are coming up (I take Eze1za’s point that it’s a very amateur trial as I did not use proper controls but I am just a curious amateur).
So far of the various seeds planted in the Southern hemisphere summer – January 8, 2011
 I have:
 C bivonnae 15 seeds – 12 seedlings
C. stevenii? (M Harvey’s seed and question mark) 22 seeds – 12 seedlings
C parnasssicum 25 seeds – 2 seedlings
C cupani  - nil seedlings to date
C. triphyllum balansae nil
C. longifolium nil
C, boiserri nil
C. variegatum nil

As the ones that have germinated have come up within the past fortnight and it is still technically winter here, the other seeds may yet germinate.  I wish now I had done as Ezeiza suggested and put some seed aside in the conventional manner to compare the two treatments. Anyway it is fascinating that any seedlings have come up at all given that the temperatures in the pots rose to 45C during summer.

Anita