Corydalis in winter

[Brian W]

Has anyone tried transferring pots of Corydalis Section Leonticoides in mid-winter from the greenhouse to outdoors?   Have already done this for half of mine (about 20 large pots) where the shoots are already well emerged.  So far no hhint of a problem, but starting to get uneasy, as snow showers are forecast for some days.  Tubers were wetted in the last week of November, so have been growing for seven weeks.
C. maracandica seems the toughest in this section and have had one cv planted in the open garden (Durham, England) for the past ten years.  Other Leonticoides have always been returned inside by mid-May.   Have attached a picture of C. sewerzowii from early March last year to show what I'm hoping to see in a few weeks time.

[Maggi Young]

Hello Brian- welcome to the Forum.
Attempting such a transfer is not something that we would try.  Although some plants of that section are hardy enough when grown out in the garden, a transfer at this time of year, especially with advanced shoots, seems very risky indeed.
Janis Ruksans, with tremendous experience , growing  in Latvia (though he admittedly has tougher winters that either yourself or us here in Aberdeen, North East Scotland) would not risk such a move, I am sure.

Presumably you will not be able to even sink the pots in the open ground at this time of year to give the pots a measure of protection - and arranging overhead protection would be tricky to any extent  when there is "soft" growth existing.

[Maggi Young]

This thread was opened in the Member's area of the Forum: as this section of Corydalis have markedly swollen tuberous storage systems, they more than qualify in Forum terms as "bulbs"  so I have moved this thread here.

[ChrisB]

I'll certainly be interested in how it fairs outdoors Brian.  Do keep us posted here.  Ok to try these things out if you have 'spares' - I used to do such things with diascia species when I had the collection.  Not many managed to survive though....

[Janis Ruksans]

Janis Ruksans, with tremendous experience , growing  in Latvia (though he admittedly has tougher winters that either yourself or us here in Aberdeen, North East Scotland) would not risk such a move, I am sure.

With Leonticoides section it is very risky. I several times lost my outgrown Corydalis from this section because night frosts killed foliage. When it happens three seasons one by other - tuber used all food reserves and didn't come up more. Those from section solida are different. They has underground scale leaf on stem with sleeping bud and if surface foliage is killed, this bud awake and makes new shoot.
This year rodents cutted stems of solida section species just at tuber - so were lost this stem's scale leaf, too. So now I wait spring to see - will be  new stem formed or not from tuber as well as new roots, because tubers were collected and replanted from rodents deposit in mid winter. All autumn growth (roots and stem) were cut off.
Janis

[Brian W]

Thanks for all the advice and will definitely be more cautious next year.  However, ten days of snow on top of the plants caused absolutely no problem and several cultivars seem to have continued growth under the snow, in particularly one of the C. popovii.  One of the pallets with pots, including this popovii cv shown.   Now they have got the challenge of a strong wind.

[Maggi Young]

 I am pleased that the pots did not seem adversely affected by their ten days in the snow, Brian. I would think that the snow cover was the reason for their survival - giving  insulation to the pots. Long exposure to prolonged freezing, especially without snow cover - what you will see forumists refer to as  "black frost" would be a different matter and would be much more dangerous.

[ChrisB]

True, Maggi.  But I wonder how they'd do if they were actually planted in the garden?  We don't tend to get permafrost in the ground without snow, so that might still mean they can be kept outside in the garden.... but would one risk it?..... that is the question.

[Maggi Young]

In Aberdeen we can have frost  down to around 15 to 30 cms  without snow and it  is has been known to freeze water pipes, which are around a metre underground in extreme cases! That might not be a problem  for Brian - but it's not something we'd risk.