Photo in Image Gallery-Saxifrages

Had to search Wiki a bit to find the picture
(http://www.nargs.org/nargswiki/tiki-browse_image.php?galleryId=55&sort_m...)
but I think the yellow one in flower is one of the cultivars of Saxifraga x paulinae (such as 'Paula' or 'Franzii') which comes from the crossing of S. burseriana and S. ferdinandi-coburgi. And to the left of that - you might need to zoom in a bit - is a nice old-fashioned pink flowered hybrid, possibly S. x edithae 'Bridget'. Not enough to go on with theones at extreme left and right though.

Thanks, Malcolm! After reading your response I reached for your book for more info. Sadly, reading constitutes my sole experience with saxes so far, (except for seed from the SEEDEX I just sowed today). Unless the trough pictured is enormous, I was surprised to see how finely-textured the cushions were.
They appear to be planted in/on tufa. Do you suppose each was originally a single plant in a hole , or several plants that spread to join? And would the plant root in the holes in the tufa as it crept and so become many individual self-supporting plants?
Now it's time to go to the online catalogs and search for these Kabschia and marginata crosses to try in my faux tufa mounds!  J

AS far as the trough is concerned I would estimate it to be around 30 in by 20 in so not enormous. And thinking about the pink-flowered sax again it could be a S. x kellereri if it is not S. x edithae. Either way it is one of those crosses first made by Sundermann before the First World War. Still can't get to ID the ones on extreme right (which may be two different plants - one on the tufa and one in the surround) or left but there are many which make big cushions of very small rosettes.

As fara s planting is concerned I would guess that all the plants started as single individuals - many will certainly make adventitious roots as they go rooting as the cushion gets larger if the cushion is a fairly dense one. What you can see tho' is that the pink-flowered one is not managing this - bigger rosettes and less dense cushion.

Good luck with hunting some more sax's down.

I have grown these sort of sax's from seed. I firm my seed mix firmly in the pot (with the bottom of another pot) then sprinkle a little bit of silver sand (the very fine sand they sell for aquaria - which is so fine it runs through your fingers - like in an old-fashioned glass egg-timer) across the surface and sow the sax seed on that. If the pot is going to go outside then I will then scatter a very thin layer of gravel on the surface but if I can am going to keep it under cover in the aline house then I will probably not put any gravel on it so I can see what is happening. You can always add gravel a piece at a time with tweezers once you have germination.

If the seed is fresh then it can germinate in about 10-14 days - if its from this year's seed exchange and you have sowed it already then hope that you might get some germination this spring.

The seed I received from the exchange is, I believe, more of the rosette-forming types rather than mats, except for S. bryoides. I still need to do more research,but I got oppositifolia, paniculata v brevifolia, and (disappointingly) three! silver mixes. Also S. caesia and arendsii. So I think I need to purchase plants.
Arrowhead Alpines has two x edithaes, an x landauri, cochlearis minor and paniculata minutifolia, all of which I believe might be appropriate for a large chunk of tufa, no?
I've been making hollow hypertufa-ish rocks - some simulating tufa - filled with growing medium, and I've experimented with direct-sowing seed into cracks in the rocks. I was thinking of trying the bryoides, but I read that it likes acidity and so might object to the concrete. Is it very particular, do you think? The rocks were soaked in mildly acidic water to neutralize them, but still...

I've never found S. bryoides that easy. Although it will germinate and do okay through the first year I find it difficult to keep through the winter. I find S. aspera which is from the same group easier.

The advantage of some of the others you've got is that you should get some germination and they will grow on and survive. Sax. oppositifolia can be very good from seed although I find that confining it in tufa is not to its taste - it seems better with a freer root run. S. paniculata brevifolia can be great. And the silver mixes can be irritating in that you may never have a name for what appears but you could get really nice things which will be adapted to your conditions. S. caesia can be grown from seed but definitely does need tufa to flourish at all - not usually easy. S. arendsii will be a hybrid mossy saxifrage - no more definite than that.

Just looked at Arrowheads list - the ones you mention will grow on tufa - you might want to brighten them up with one of the newer hybrids which Harvey Wrightman lists.

My hypertufa-ish rocks, however, are hollow, like a shell of tufa with growing medium filling, so theoretically (they're not old enough to have proved themselves) they should have the aesthetics and perfect drainage of tufa while also providing a welcoming substrate for roots.
Thanks for the Wrightman tip, he wasn't on my list of regular providers. Being in Canada, I wonder if I'd need special import certificates? Info is probably on his site, I'll go look.

Using Hugh's instructions on how to include images from the Image Galleries in messages, here's the trough we've been talking about.

Holy c--p!!! Now that's a trough "to die for". There are times I wish Tennessee wasn't so humid in summer. Thanks for sharing this great photo.

Malcolm, Wrightman's was one of the vendors at the EWSW, and without the shipping costs I enabled myself to buy three saxes, 'Jana', 'Cambridge Seedling', and S. sp. 'Betscho Pass Siberia', all in full bloom and each growing in its own chunk of tufa.
Now I don't know what to do with them! Bury them in the dappled afternoon shady sand bed? Maybe in a trough, or a pot? I'd like to let them outgrow their tufa chunks so I can eventually divide them, which I assume I can't do now because their roots are inextricably bound to the tufa. Or perhaps I shouldn't be waiting for division but should instead be thinking of taking cuttings after the blooms are gone.
I also wonder about hybridization. Would something as crude as using a cotton swab on a stick work? I'd like to try crossing the large white 'Siberia' with the small rose "Jana" and see what kind of results I get.  Assuming they're even compatible; I have no information about their backgrounds.
I'm just excited to feel that this is a start on spring activities!

Sorry I've been too busy to get round to posting you an answer sooner.

I think I wouls start by growing them in a pot - maybe even putting all three in a larger pot - say 12" - but I would definitely take some cuttings after they have flowered. Then they will be at their most vigorous and cuttings should root in just a few weeks.

As far as cross-pollinating is concerned I take the stamen off one plant with a pair of very fine tweezers and then take that to the plant I want to pollinate - that way you make sure you get enough pollen on the stigmas. In all these cases there should be compatibility but the most likely to set good seed is the 'Betscho Pass' plant since that is species where the others are hybrids - in both cases the parentage is not really known. I would try in both directions but would expect more chance of seed setting on 'Betscho Pass' pollinated by 'Jana' than the other way round. 'Jana' probably derives from a Saxifraga x anglica hybrid but 'Cambridge Seedling' but again probably one of the parents is similar but then crossed with S. marginata although this is conjecture. 'Cambridge Seedling' has been around since at least 1971 but 'Jana' is much newer and originated in the Czech Republic.

If you do get seed then I sow the seed immediately the seed capsules start to open (perhaps 8 weeks) and often you will get immediate germination (say 10-14 days). It's great fun to get such an immediate result. Sometimes they will flower in their second year of you are lucky. Good luck.

Malcolm,
Thanks so much! Exactly what I needed to know. Maybe this thread should be moved over to Propagation?
I'm going to transplant the Saxes into large pots with a 3 cm top-dressing of small gravel and coarse sand. They are currently in tufa blocks which are perched way up in plastic pots, but I don't see any reason to continue that positioning and plan to sink the tufa so it's just 1-2 cm above the surface of the gravel. I reckon that will keep the tufa from dessicating but still provide good drainage. And enable the plant to easily colonize the surrounding 'soil' when it outgrows the tufa. What do you think?
I'll try both directions with Jana and Betscho Pass. So, I'll know this year if I have seedlings! I'm excited about this!