i want to grow some saxifraga umbrosa(london Pride)

The seed of Saxifraga is indeed very fine, Mungomum. The first thing is to hope that the seed you have comes from a reliable source and is viable. I would have taken a small pot of soil based seed compost and sown the seed thinly on the top. After covering the seed with a very thin layer of grit, just to stop the seed blowing away, I would have given the pot a good soaking and then put it in a shady spot to await germination. Cold stratification is not strictly necessary but the pot will not mind being frozen in the winter. If I sowed freshly collected seed at the end of summer I would hope to see seedlings appear the following spring. Good luck next time.

thanks so much. where are you? the climate here (zone 4) is alpine and i'm pleasantly surprized at how many of my plants (new garden) survived the winter, but it is undeniably cold. i bought seeds from a reputable nursery - chiltern seeds. nothing came up; everything else in my garden came up from seed, though we had a very late spring. i put in the fridge as instructed, then placed under grow light. nothing.
the nearest supplier of live London Pride (in fact the only supplier i found) is in Spokane, Washinton, over the US border. i spoke to them and on the whole, what with security restrictions and mail delays, they thought it wd be unproductive even to attempt to bring them here. so i'm stumped.
if you cd recommend a seed house? you can email me if you'd rather not mention names...
i do so appreciate your kind reply.

I am in the north of Scotland, Mungomum, where it grows like a weed. I was away from home for a few days and hoped to be able to send you some of my own seed - however, it does not seem to have set any :-((((, so, sorry.
I have also looked on the web for seed and, appart from Chiltern, no one seems to be offering it there either.
I did find one person offering plants on ebay, but they are in the UK. I would assume that you have ebay, or similar, in Canada so maybe you could try there.
Other than that I am afraid that I cannot suggest anything. Well, Amazon.com does have prints for sale but I guess that you would rather have the real thing.

ah. i remember it growing like weeds in both edinburgh and kirkcaldy. it's amazing that this pretty plant is now out of fashion.
but you give me an idea; i think i'll pass the word around amongst my friends in scotland and ask them to pick up some london pride seed-heads, rather than tossing them in the compost and send them to me. as you note, the seeds are microscopic, but if i can grow even one or two, then i can get a start.
are you short of bees in scotland? i seem to have more this year... we're in a dilemma here; apples in abundance, but the bears come at night and steal them. nobody grudges the bears the apples, but if they're seen, people get freaked out and send for the wildlife officer who has to shoot them.
thank you so much for thinking of sending me your seeds. it was so kind. i wonder if i should try chiltern seeds again. but i did do everything required, and neither astrantia nor london pride came up at all, though i grew some roses from seeds as well as hellbores and the usual annuals such as bacopa and petunia. i'll keep my fingers crossed - i'm a devotee of gertrude jekyll and she loved them. cheers!

thanks for everything bulbaholic. my hot news is that i have found a supplier - about a thousand kilometres away, but at least in canada. they will deliver - the nursery seem quite sanguine about the ability of London Pride to survive the winter....we'll see. they recommend planting late in the year. i have to believe they know what they're talking about.
a' the best, from a Scot abroad!

Good luck :-)