Cypripedium dormancy

[Alex]

Hi all,

I wonder whether anyone else has encountered this problem. I have a few new Cypripedium species this year, and many of them have yet to appear. Thinking it a bit late, I have investigated, and found that the plants seem fine underground with healthy shoots that are just not growing. Maybe some of them are later risers (shanxiense, micranthum and lichiangense) and perhaps still could appear, but I don't think that's true for the likes of my new candidum seedling, a species which is quite early up normally. All of my other plants that I've grown for a few years are up at their usual times, and these include a few of the same species which are still dormant. Any thoughts? Is this common for new plants in their first year growing under different conditions?

If the dormancy persists, my plan is to keep them moist throughout the growing season, but less so than if they were actually growing. I have done that before and it seems OK.

Thanks for any help,

Alex

[SteveC2]

My lichiangense is sitting as a perfectly healthy looking bud but refusing to grow.  I suspect lack of winter is cause.

[Steve Garvie]

I suspect that most of us got lichiangense indirectly from the same original lab-raised source.

My two plants also remained inactive. However about 9 days ago I decided to risk exposing them to some "gentle" heat in a sunny frame (which has shading that I can directly control and variable ventilation). The temperature was monitored by a digital max-min thermometer. My plan was to create a significant daytime temperature lift but keep the evenings cool (apart from one lapse in attention when the temp peaked at 28.9C, the daytime highs have been 18-24C and the nightly lows at 3.5-6C). This has done the trick as one plant has produced a sizeable (non-flowering) bud which is progressing well whilst the other has two small buds which seem to be taking off.

The above brings two problems -without care the plants can be cooked. Secondly if humidity is high the sheath which covered the dormant bud is very prone to fungal infection in warm conditions (this happened to me many years back when the first spotted-leaf Cyps hit the West).

Once the buds start to move I would give this "sheath" a dusting with flowers of sulphur and give the plants maximum ventilation but with some overhead protection from rain and grow as cool and as well-ventilated as possible.

Re-reading the above, it sounds like I've set myself up as some sort of expert -sadly I'm far from that!  .
I first grew these plants about 12-15 years ago. They were bought from a Danish importer whom I think bought them from Chen-Yi. Most of the plants were un-named, a kind of lucky dip and sadly I suspect that all were ripped from the wild. Attrition was high on receipt but those that initially survived lasted a few years. None of these plants survived long term though lichiangense, margarataceum and wardii all flowered in their second season. The Spot-leafs all eventually developed crown rot or botrytis of the new buds due to overhead watering/excess humidity with poor ventilation and wardii (which grew well in an open sphagnum mix -as per Pl. forrestii ) froze solid at the end of its second winter. To be fair my interests drifted elsewhere at the time, with more care I think they are grow-able long term.

[Alex]

Thanks for this, Steve(s),

It does seem plausible that the plants aren't getting the normal temperature rise they are used to in order to signal Spring, since Winter here was quite warm. Accordingly, I have brought them out into the growing area to increase the temperature differential a little more. Having said this, I was pleased to find just now that one of the persistently dormant plants has just started to take off, so hopefully the others can still follow.

Steve G: yes, the lichiangense is no doubt the same as everyone else's, from Camiel de Jong originally I think although mine came via Laneside. Your musings on growing some of the first importations of Trigonopedia species from China brought back memories, as I had a few of those Chen Yi plants too back in 2000. For me, they all came up that first year and were never seen again....I wasn't growing them quite like I do today, although they were in a very similar Seramis-based compost; however, it was far too dry when the plants were in growth. No doubt the lack of roots didn't help either.

Cheers,

Alex

[Stephen Vella]

Alex I had flasks of lichiangense all died now after 4 yrs and found they were late coming up.. Could be a response to higher temps as mentioned or moisture as I was told to water from beneath and not wet the leaves. Well I became slack and watered the like the others and they went backwards fast.. How do they cope with rain in nature I say.. Must be dry when in growth in the wild with moisture seeping beneath.  Hard to figure this one.. Good luck

[monocotman]

Alex,

I'm pretty sure that the extra mild winter has affected the growth of some cyps. They probably did not vernalize fully.
I have some froschii and macranthos clones that have only put up poor weak growths that are quite pale.
Also two x ventricosum alba clones.
I've never seen this before.
I don't have anything that has not appeared at all but there are several plants that are not happy.
I think you're right just to keep the pots ticking over and see what happens next year.
Stressed cyps have been known to take a year off and come back as though nothing has happened.

Regards,

David

[Maren]

Hi,
I have a number of C. kentuckiense and others that didn't show. On inspection, they all have healthy roots and good looking buds that just seem to be stuck in development. I have re-potted them and hope they survive. They won't catch up with the others, which are in bud ready to flower, but it would be a pity to lose them.

[SteveC2]

Any updates on the lichiangense folks?

[Darren]

I don't grow lichiangense but the plant I saw on the Laneside stall at Holker Hall last Sunday looked like it had only just woken up and had an emerging leaf only about 4 or 5 cm long.

[SteveC2]

That's big.  My leaf is about 2 cm long.

[Steve Garvie]

Don't want to tempt fate but both my plants have multiple growths & each has a visible flower bud.

I don't dare show an image at present as after posting an image of Cyp. fargesi my plant has developed a scorch line on the end of one leaf.   

It is plunged in a heavily shaded frame but unfortunately my wife's cat sits on top of the frame & on one of our recent very sunny days the cat displaced the shade cloth allowing a narrow beam of sunlight to laser the end of one of the leaves!

The problem with these spot-leaf orchids is it just needs one little lapse in attention for the plant to sustain damage that can lead to terminal decline.
.......And how can one possibly get through a whole growing season without taking an eye off the ball -even just briefly. 

[Maren]

Hi,
you can solve your shading problem by painting the window from the inside. Then your wife's pussycat can't be blamed.

[Steve Garvie]

Cypripedium lichiangense now in flower. A second plant will flower soon.
A quick image here, I will post better images in the Cyp. thread later.

[monocotman]

Great flower and photo!
David

[angie]

Great flower and photo!
David

Better than I did 

Angie