Scottish Rock Garden Club Forum
Cultivation => Cultivation Problems => Topic started by: Cephalotus on August 12, 2008, 08:34:11 PM
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Hi everyone,
I have some big problems with two Saxifraga: caesia and oppositifolia. They both almost died in my garden. As I know, both of them like to have lime in the soil. I grow them in full sun and they have sandy and rocky soil. They look so miserable that I am afraid to show them. They got yellow and than brown. Can this be a fault of the 30*C temperature? That day I lost two Geum montanum, one Viola alpina, also one S. caesia. :/
Does anybody know how to grow these species? Maybe I should grow them in half shade? But I am afraid, that they won't flower in such as conditions. Before I get new ones I must know what I did wrong and what can I do to change that. I have no influence on the temperatures outside. :/
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While I don't know your climate Krzysztof, I do think it is likely that your saxifrages are too hot. I find they burn very easily and so I don't grow them in full sun. The silver or encrusted forms do take more sun than S. oppositifolia but even with those, I like their soil to be cool, damp and moisture-retentive (humus and grit). It is the nature of saxifrages to grow in shady places so their flowering is not inhibited by shade and in fact, is all the more beautiful for being away from direct sunshine.
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Thanks Leasley, I will put them in shady place and see what will happen than.
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I agree with Lesley.
I used to grow my sax on the open bench and they all used to die.
I gather its the root temperature that's important.
In the sunny South Midlands we have Summer temps of 30-35C.
Keep the roots cool.
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Even up here in 'sunny' Scotland I find that Saxifrages can burn easily. I used to have the smaller varieties in the alpine house but they never did well. Now they are outdoors and doing better.
I grow oppositifolia outdoors in full sun but with the roots beneath some imported limestone rock and they love it.
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In the sunny South Midlands we have Summer temps of 30-35C.
Really? Globe must have warmed massively since I was last there. :D
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-it's not called 'The Apricot Village' for nothing....
http://www.aynho.net/
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I have seen Sax. caesia in the Dolomites growing in blindingly white limestone in full sun and flowering happily. I have also seen it in the Tatra Mountains in damp shade also looking happy. I agree that a cool root run is probably best and would suggest a crevice garden/trough.
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But how can I keep low temperature of the soil and the roots when I have 308C temperature in shade? I know that some have special automatic watering in the soil, so the temperature and humidity of the soil are always optimal. Still I have a tiny rock garden. I do not want to grow species that I can grow well and never see any flowers. That isn't what I mean. I was afraid to know that S. oppositifolia need to grow in full sun. :/ I thought so, since it grows in high mountains here in Poland. It had low temperature in nature, wet soil and full sun. That are conditions impossible for me to provide. I thought that there may be something in exchange that they will grow and flower. I will try with the shaded conditions. I will put some smaller stones behind the big ones and plant both Saxifraga there. If they will do much better in next year everything will be clear. Or maybe there is some simple way to lower soil surface by some place changes?
I watched so many photos of S. oppositifolia on Internet, that I even got woeful. For example like that. I am dying to have such as view in my garden: http://www.gtpoulsen.dk/Saxifraga%20oppositifolia%20var%20paradoxa%201.jpg
A small off-topic. When my Swertia perennis flowered I just couldn't stop staring at it. It is still flowering and I cannot come off from it.
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-it's not called 'The Apricot Village' for nothing....
http://www.aynho.net/
So where's G Reed in all this?
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Krzysztof, if your saxifrages are in full shade (troughs on the shady side of your house perhaps?) they will likely be able to cope with a warm air temperature if the compost is cool. This can be acheived by a thick topdressing of gravel or lime chips, or flattish rocks. Water in the evenings and they should be able to withstand the day temperatures.
I guess that if you want the plants enough, you'll learn to be innovative. So many of the things we'd like to grow are not "naturally" at home in lowland or coastal gardens (as here) but we find it worth an effort to provide what they need because we love them so much.
Many of New Zealand's alpine plants (natives I mean) withstand searing hot mountain temperatures, in full sun but need cool, shady places in the garden. Sometimes the mountain rocks are too hot to touch yet the plants are draped or growing on these. However, the roots are way down deep in cool cracks or crevices. As Giles said above, cool ROOTS are the secret.
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Krzysztof - Good advice from Leslie. When I grew S. oppositifolia in a trough I would pull the shade cloth over it when it got above 28c with humidity. I always watered heavily before the hot humid weather arrived and then held back on water during a heat wave, especially night heat above 20c. Both these scenarios are short-lived here.
The last 3 or more weeks here have been very damp. I have to move newly potted rhodo seedlings under plastic cover to avoid getting too wet. Tonight there are heavy showers with thunder in the distance, constantly I'm moving flats in and out every few days. The huge banana slugs are about to take flying lessons.
I'm afraid this wretched weather is probably headed east to the UK.
johnw
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I have seen Sax. caesia in the Dolomites growing in blindingly white limestone in full sun and flowering happily. I have also seen it in the Tatra Mountains in damp shade also looking happy. I agree that a cool root run is probably best and would suggest a crevice garden/trough.
Also quote by Lesley Cox:-
Many of New Zealand's alpine plants (natives I mean) withstand searing hot mountain temperatures, in full sun but need cool, shady places in the garden. Sometimes the mountain rocks are too hot to touch yet the plants are draped or growing on these. However, the roots are way down deep in cool cracks or crevices.
Saxifraga oppositifolia also grows in very exposed situations (in full, burning sunshine) in the Dolomites (see images), but appreciates half-shade and a cool root run in the U.K. Another paradox for those of us who love growing alpines.
Piz Boe - A frequently hot and exposed habitat of Saxifraga oppositifolia
Saxifraga oppositifolia
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Saxifraga oppositifolia and all other alpine plants grow and flower only at those places that the plants like. The seed germinates at many places however a plant survived only in suitable place.
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Frantz, I know everything you said. But I bought plants not seeds. The problem was how to plant them so it would be suitable for them. I decided to cool the root system, I made topdressing with white basalt. I hope that will help. Still I will have to wait for the results till next year.
I am sure that there is always a solution and a method to grow a plant. I had some big problems with Cortusa matthioli in my climate because my weird weather. Once it is drought and hot like in oven and than one week of storms come. Growing many plants like in natural habitat didn't work at all. So I mixed special soil, put the plants in half shade and voila'.
There is some funny story with that thick topdressing with gravel. My cousin had big problems with neighbours cats. They ruined her rock garden and dug out the plants. She decided to put a "thick topdressing" of white basalt and cats stopped to destroy her garden. I was always wondering why her plants did better then mine. She also has some same species as I do and has many small species of Saxifraga. They all grow fine in full sun with the same temperatures I have (the same city). And after Lesley mentioned that solution of cooling the soil everything was clear to me. By accident my cousin did a cat-safe garden and Saxifraga paradice. :D One solution two benefits.
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And the fact it was a white basalt gravel helped even more, as the white reflected more of the light and heat, thereby keeping the soil cooler too. So probably not only the gravel, but the colour of the gravel helped.
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Don't worry too much Krzysztof - if it's any consolation, I have a number of S. oppositifolia labels left as silent witnesses of the ones that I lost over the years... :'(
In my climate - probably a little wetter than yours, but also with the occasional hot spell with temperatures over 30°C for 5 or 6 days or so (not this year !!! ;D) - I didn't manage to find a suitable place for them to thrive. I find them very difficult to please over here... which doesn't mean I won't give them another try in future keeping in mind the new clues I just read from the specialists on this wonderful forum ! ;)
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It is a long time since I grew Saxifrages with any success. but I learnt a little.
Oppositifolia is not a pot plant. It needs a little space and it needs water.
I would actually try to use very gravelly soil and have some drip irrigation running all the summer.
It is not the sun or heat that seems to be the problem it is lack of water.
Of course I am at nearly 60° North
I found that kabshia saxifrages did best when the pots were constantly watered from below.
A pot on the bench is not the best place in my opinion.
Crevices in the mountains often carry water from glaciers.
Good luck
Göte in mid Sweden.
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Krzysztof,
The culture of alpine plants in the garden is wonderful. But some kinds are difficult in some garden. I tried many methods out in many places in my garden.
I am trying after 50 years still!
Look at the pictures. The Saxifraga oppositifolia grow 10 cm far away and have the same soil, stone and sun.
By the way. One alpine plant is a problem plant!
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Franz, you are a very wise man.
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Franz, I don't believe the lower plant is yours. You must have photographed it somewhere else. ;D