When to protect Meconopsis and other seedlings from the cold.

[Sheep]

Hi Everyone
Could somebody possibly please answer a very basic question for me? I have studied various books and websites but this one has caught me out!
I am facing my first ever Winter with outdoors plants. I have spent the year trying to protect my seedlings from the the sun and not given a lot of thought to the cold because I believed that they would shrug it off. However last night we had the first warning of a frost and it occurred to me that many of my seedlings are still very small which made me wonder if they are vulnerable after all.
The majority are Meconopsis, some evergreen rosette forming and some horridula types. I also have some Asiatic Primulas, Saussureas, a couple of Gentians, a Gladiolus and some Irises (chrysographes, Pacific Coast and Siberian).
Some of the M.paniculata and wallichii have got a little bigger, but the aculeata, prattii, racemosa and rudis all look wispy and vulnerable to my inexperienced eye.
The solitary M.delavayi began to shrink a few weeks ago.
They are in Wilko greenhouses. I removed the colourless covers in the Spring and replaced these with shade netting.
There is one big plant doing well but it is a year older and spent last winter in my bedroom.
Many thanks in advance.
(By the way I am not trying to create a garden full of unknown hybrids. Last year I realised that if I am to be successful I need all the experience I can get. The chances of me ending up with more flowering than I can segregate are slim I would say!)
Kind Regards
Nick

[Sheep]

Photo

[Sheep]

Mostly M.aculeata. Also the Sinopodophyllum hexandrum at the front.

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M.racemosa.

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The only one that I am not worried about. The sole surviving M.paniculata BVH42 from last year.

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M.racemosa better quality image.

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Selection brought in

[Tristan_He]

Hi Nick,

I overwinter all my alpines outdoors, either unprotected or in a frame. I think the elements do them good, by and large as many species need a prolonged cold period to stimulate growth and / or flowering in spring.

HOWEVER, many species may need protection from winter wet (especially Himalayan species). The extent to which this is necessary depends on how wet a winter we get, the species concerned, the size of the seedlings (as you say, small ones can rot off more quickly), and the drainage of your compost (I generally put a layer of perlite at the bottom of all my pots with smaller seedlings in). To be honest most of the plants in the photos you posted look big enough to plant out, never mind overwinter!

Some possible solutions for small seedlings:
- Put them in a frame with the lid on but partly open (so some rain can blow in and they don't dry out) - this is the best thing to do I think.
- Raise the pots / trays up to ensure better drainage (you often get a film of water under them)
- Repot into a more freely draining mix (though probably not great to do this now)

Hope this helps - don't think you have too much to worry about though.

Best, Tristan

[Carolyn]

I agree with Tristan's advice, but would add that PC irises need a bit of care while young. They do not like cold wet winters. I bring my young plants into my unheated greenhouse in winter and plant them out in late spring so that they have a whole season to establish before they have a winter outside.

[Sheep]

Hi Tristan, Carolyn,

Many thanks for all the helpful advice. I will leave everything except Iris innominata outside and place some protection against the wet.

Thank you.

Best, Nick