Temperatures for these seeds

[Rob-Rah]

Good morning,

I wonder if anyone can say what temperature regime is effective for germinating these seeds? If I don't find out, I'll put them all into the cold (frost-free) greenhouse and subject them to the typical Mediterranean regime of cold nights (0-5C) and rather warm days (up to the high 20s) which a sunny greenhouse can supply for the next month or two - I think that feels more likely to succeed than a propagator at 24C.......

Aristolochia chilensis

Sideritis cypria
Sideritis euboea
[I have had reasonable success with other Sideritis with the cold greenhouse method]

Sonchus fruticosus (Madeira)

Micromeria fruticosa


Many thanks!

Rob.

[François Lambert]

Hello Rob,

I don't know these plants, but indeed many seeds will have better germination when natural temperature conditions are replicated,  including day/night swings.

When I sow seeds I always try to imagine what the climatic conditions are once the seeds have dropped on the soil.  This helps me also in figuring out what kind of stratification a seeds may require to break dormancy.

[Rob-Rah]

Yes agreed. My doubts are mostly on the Aristolochia chilensis: I am unable to find much even about the conditions the plant grows in, with the internet suggesting everything from classic Mediterranean through semi-desert to warm-temperate :/

I have a hunch the Sonchus might be a better bet in the propagtor: I've seen it wild many times in its various habitats.

[Ben Candlin]

Hi Rob,

If the seeds are fresh you will find that the Sonchus will germinate very readily under warm conditions (ie, propagator). They should be easy to start off this way.

[Rob-Rah]

Thanks - not sure they are all that fresh :/ Bought last year but there's never much guarantee bout freshness from many shops. We'll see, now they're in the mid-20s in a propagator.

Does anyone here grow Aristolochia chilensis?

[Roma]

I grew Aristolochia chilensis a long time ago when I worked at the Cruickshank Botanic Garden in Aberdeen.  I think I may have had 4 or 5 plants grown from John Watson's seed.  The seed was probably sown in a propagator which was not switched on but sat above the heating pipes at the end of a long corridor.  The temperature was about 60 F.  The plants lasted a few years .  The greenhouse they grew in was heated to about 50 F but would have dropped lower when it was really cold. (I use Centigrade mainly now but my memory of temperatures at work is still Fahrenheit).   I think there were still 2 or 3 when I retired but interest in greenhouse plants diminished and there was no one with specialist knowledge or the same enthusiasm for interesting or odd plants that I have.  Greenhouse space was also much diminished.  The leaves are very attractive but rather smelly.  The flowers are fascinating.  I must see if I can dig out some old photos.  I did get seeds of the white form later but did not succeed in germinating them.

[Rob-Rah]

Hi Rob,

If the seeds are fresh you will find that the Sonchus will germinate very readily under warm conditions (ie, propagator). They should be easy to start off this way.

Sonchus are already up! Looks like a high rate of germination - I will have far too many plants.