Scottish Rock Garden Club Forum
Cultivation => Cultivation Problems => Topic started by: Philippe on September 13, 2011, 06:26:11 PM
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Hi
Has anyone already tried to grow the nobile?
I planted some seedlings of it a few days ago. They won't have been frightened by the weather in the meantime: fog, clouds, and permanent drizzle are on the program since then ;D
I was wondering if the nobile was rarely ( if never?) seen in the weather-favoured gardens ( private or botanical) because of its relatively new introduction ( am I right?) or simply because even in those blessed gardens its culture was still very difficult.
Rheum alexandrae grows without any problem by me, even in purest peat and without any care, but anyway it might be of easier culture then.
But would the superficial likeness be a little clue to any growth/climate requirements similarities with nobile, or not at all?
I spent so much time on preparing place and soil for the nobile! I dare not to say how long it took me before I could finally plant the "magic" seedlings in what I think to be the best place/soil...For the moment!
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I have grown a number of rheums and appear to have success with them, however, Rheum nobile, I believe needs very sharp drainage. If you look at the habitat it comes from, it appears to be rocky slopes in moist conditions. Of the 3 people here in Dunedin, that had a plant each, we all lost them. We realised that keeping it moist is essential but not "wet", as they all rotted off.
There is a fabulous photo on the front of an AGS Bulletin from some years ago (about the seed collecting trip to Sikkim, if I recall) and it is not in a bog but on a very rocky and quite steep looking slope
Good luck with it, would love to get seed again so I could give it a go in a more appropriate place.
Susan
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I had 3 from seed and they all rotted off over three years. It almost looks like a scree plant.
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Thank you for your answers Susan/Lesley.
I added grit to the soil for the drainage, but my first guess, having already seen pictures of its environment, was that I didn't really know how to imitate the natural conditions in which it grows: somehow I can't "imagine" such a giant plant thriving in the scree environment, although it is of course. Such big leaves, such a stout root, such a height! It's so easier to think of smaller and creeping plants in those conditions...
I still have a few other seedlings who will overwinter in pots with well-drained medium, and 2 directly in the propagation bed ( where the earth is not really of scree-nature, but generally still "alpines-friendly" for a short stay of 1/2 seasons).
Let's see who will do the best amongst these three "groups".
I pray they're not all dead when I come back next spring...That would make me enrage >:(
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Perhaps a silly question...but could be generally said that if plants generally requiring faultless drainage ( for example the north american lewisias) thrive well in the open air without any protection against winter or summer wet, it would mean that the soil itself, at least, could also satisfy a rheum nobile regarding to the precise and only aspect of drainage??? (beware, I don't take consideration of the atmospheric conditions or other still ununderstood needs in the particular case of the nobile)
I have grown a number of rheums and appear to have success with them, however, Rheum nobile, I believe needs very sharp drainage. If you look at the habitat it comes from, it appears to be rocky slopes in moist conditions. Of the 3 people here in Dunedin, that had a plant each, we all lost them. We realised that keeping it moist is essential but not "wet", as they all rotted off.
There is a fabulous photo on the front of an AGS Bulletin from some years ago (about the seed collecting trip to Sikkim, if I recall) and it is not in a bog but on a very rocky and quite steep looking slope
Good luck with it, would love to get seed again so I could give it a go in a more appropriate place.
Susan
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If I understand your question correctly Philippe, then the logical answer would be "Yes" but as you recognise, there are many other factors involved. Without knowing why, we all lose plants beside perfectly healthy and strong plants, yet they should require exactly the same conditions of soil, drainage etc. It's a shame with Rheum nobile, that there's virtually no material available with which to experiment.
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No worry Lesley, I do intend to flood the all world with garden collected rheum nobile seeds in about 7/8 years ::)
Last winter we got a few seed from the Göteborg botanical garden in Sweden. Apparently (?), this was not wild collected, which could have meant it was collected in the garden itself, but really not sure. I should try to write them to verify. ANyway, I didn't find any informations about a rheum nobile in culture there, or anywhere else, that's why I also asked here on the forum.
The other source last winter was Holubec wild seed through the AGS seed exchange, from which we could get 5 seeds ( only 1 germinated last spring. The seedling is still in the sowing pot, looking good and waiting until next spring to see if the other 4 are going to awake or not).
And we were also given generously 3 other living young plants from the Lautaret alpine garden in France.
With all that I have at least a little material to "experiment" the culture for the first time here.
I'll tell how/if it is going next year.
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Very best of luck with your plants and seed Philippe. I hope it is successful, especially if it is good in a pie. ;D
In pictures we see the magnificent flower stem but I don't recall ever seeing the foliage. I mentioned having had 3 plants which all eventually died but in truth, I don't know if they WERE R. nobile as they were from seed and didn't grow big enough for me to be sure. They were not like any other Rheum I've grown and the leaves were rather deep green and glossy on red stems. I can't remember where the seed came from but probably the AGS.
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Ok Lesley, I'll tell you how it tastes, a rheum nobile pie :P
(http://kevinspence.com/IMG_0175%20(2).jpg%20alp.jpg)
Looking at this picture, I get horrified: those dried brown stalks...Looks like the nobile flowers itself to death >:( If one gets seed again after, it's ok, but...
Well, another good argument for making pies, and never letting it flower ::)
Nevertheless you can see some leaves here Lesley, better on the unflowering young plants
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Yes, a bit difficult to see what the leaves are really like. The yellow base of the flowering plant could be the beginning of the stem rather than true leaves. I think it is supposed to be monocarpic isn't it? In which case one would have to rely on seed after a blooming. As for picking out the stem and not letting it flower, that would rather lose the point wouldn't it? I mean, one grows it - or would like to - specifically for the wonderful flower stem. One can dream though. :D
The landscape with those incredible snowy mounds must look amazing. 8)
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Well it's a while since we posted here but I have good news this morning (Mar 11th) in that I have 7 seeds germinated overnight, of Rheum nobile from Holubec seed. The seed was sown on February 22nd. There are several other little bumps in the grit which I expect to be seeds up within a day or so and I'll take a picture when it stops raining. That may have helped; we have had rain almost every day/and or night for about 3 weeks and the seed pots are quite wet. I guess germinating is the easy part and now I'll have to work out what to do with them as they grow a little. It may be that they should be separated and potted individually while still very small rather than disturb the roots too much. I'm tempted to try some in long tom pots with a very high proportion of gravel and grit, with a little humus. Any suggestions or advice will be gratefully received. As for flowering them, that's a long way off yet, if it ever happens.
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The first pictures I saw of Rheum nobile were in Living Himalayan
Flowers by Sasuke Nakao published in 1964.
Here are some bits of what is written by the author and his quotes
from J.D. Hooker:
When the monsoon rain season comes over the Himalayan alpine
zone, the pastures become thoroughly decorated ......the rhubarbs
grow with their big leaves.
the flowers open in the self-made warm room in which the pollination
insects are working actively........After flowering the stem lengthens,
the bracts separate .... as the fruit ripens, they fall away, leaving
a rugged looking stem.
........... the peeled stem is a superb material for salad ...... and
attentively gathered by the inhabitants so the plant is rather rare
and found often on the inaccessible cliff.
So: this is Diane again - sounds like soggy grassland rather than
well-drained cliffs might be the preferred habitat. A picture of a
grinning Nepalese with his arm around a blooming plant shows a
solid groundcover of what looks like a dwarf rhododendron. I'll see
if I can photograph it.
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Here is some cultivation advice from The Himalayan Garden Growing
Plants from the Roof of the World by Jim Jermyn (Timber Press, 2001)
grow in screes above subalpine meadow zone
in cultivation needs good light, cool deep root run into fairly rich loam with running water
below
embed metre-wide boulders in the loam to keep the big taproots cool
For seedlings:
prick out straight into deep pots and don't let dry out at all
The next spring plant out at least 60 cm apart.
There will be no leaves in winter. Leaves emerge in late April or early May
in the UK.
It will take five or six years before they flower (if they do so at all) if you
are very lucky. The rarity of this event calls for a party and maybe the
newspapers and lines (queues) of eager viewers like when that giant
arum flowers in a botanic garden.
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Well soggy grassland is what they have here right now, with nearly 50mm of rain in the last 24hrs. But they're in their seedpot in the tunnel of course. Jim Jermyn's notes sound a bit beyond me, (metre wide boulders, running water below etc) but I'll do my best. What fun it would be to have a party for the big floral event! I'll give everyone plenty of notice.
We had a rhubard pie for tea tonight, with custard. A less exotic rhubard though. :D
What a fantastic picture that is Diane. A very happy small boy. ;D
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I got hands on a Rheum nobile seedling this autumn and have tried to create a habitat for the little plant. I used two half plastic containers with a tap. I have 30-40 cm of sand over the plastic container. Now the drain is open, so it gets dry around the roots. In April, I will close the the tap so it will be moist and cool around the roots. Can not wait to see how it will work.
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Rheum alexandrae grows without any problem by me, even in purest peat and without any care, but anyway it might be of easier culture then.
But would the superficial likeness be a little clue to any growth/climate requirements similarities with nobile, or not at all?
Rheum alexandrae from Tianchi lake 3850m, Zhongdian, Yunnan. It grows in quite damp in peat soil
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OK, what's the flower in the background.
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If you mean the image with R. alexandrae it is Primula secundiflora (and Rhododendron rupicola).
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Yep, that's it.
I see I can buy it right nearby in Maine.
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Arnold, where!!?
John B
Yep, that's it.
I see I can buy it right nearby in Maine.
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If you mean the image with R. alexandrae it is Primula secundiflora (and Rhododendron rupicola).
Funny Bjarne, before I read your rupicola I was thinking chryseum. Half right. growing near the lake says something about their dislike of drought eh?
johnw
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Two more seedlings up this morning. I should have counted the seeds. I usually do if there are 10 or fewer, so maybe 12-15.
Bjarne, please explain more, your system for R. nobile. I take it the plastic containers are to be reservoir rather than planting container? Is that right? I can't see where the containers have been stowed, in the second picture, trying to match the rocks in the two. Where is the tap and where exectly is the plant?
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John:
http://www.evermaynursery.com/store/index2.asp?ID=84
Old Town Maine.
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There don't seem to be any Rheums listed in their current catalogue.
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Lesley:
it was the Primula I was referring to.
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Oh, sorry, that would explain why I couldn't see rheums. ;D :-[
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Bjarne, please explain more, your system for R. nobile. I take it the plastic containers are to be reservoir rather than planting container? Is that right? I can't see where the containers have been stowed, in the second picture, trying to match the rocks in the two. Where is the tap and where exectly is the plant?
Hi Lesley
I'm not so good to explain in English so I have tried to make a sketch. Hope you can see from the sketch how it is done :-)
The photos do not show Rheum since it is only a small seedling and the tap does not show either, since it is hidden behind one of the lower stones.
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Thanks Bjarne, yes, that helps a lot. I see what you mean now. ;)
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Well it's a while since we posted here but I have good news this morning (Mar 11th) in that I have 7 seeds germinated overnight, of Rheum nobile from Holubec seed. The seed was sown on February 22nd. There are several other little bumps in the grit which I expect to be seeds up within a day or so and I'll take a picture when it stops raining. That may have helped; we have had rain almost every day/and or night for about 3 weeks and the seed pots are quite wet. I guess germinating is the easy part and now I'll have to work out what to do with them as they grow a little. It may be that they should be separated and potted individually while still very small rather than disturb the roots too much. I'm tempted to try some in long tom pots with a very high proportion of gravel and grit, with a little humus. Any suggestions or advice will be gratefully received. As for flowering them, that's a long way off yet, if it ever happens.
Hi Lesley
Great that your rheum nobile seeds have done so well! I had found too that germination was generous.
Last year, I have lost 3 seedlings in the few weeks following repoting. Aside from the possible repoting stress ( but in my opinion not that great in comparaison with other more delicate generas), I guess the weather was simply too wet last summer, and my poting mix was probably not free draining enough.
I even wonder if, for me, it isn't more complicate to try to grow them for too long in pot during their younger lifes, or I have to find really the perfect adequation between faultless drainage and sufficient watering, according to the plant growth and strength. And there seems to be not the littlest place for any mistake in this combination. I can't keep an eye on the seedlings during winter, they have to live alone for 6 months between november and april, with or without snow cover, with or without rain, with or without damaging frosts. So, in my case, I think they can possibly get through this crucial period better if directly planted in the bed.
For the next time to come I will try to sow 2 or 3 seeds in each sowing-pot, wait the summer months to let the seedlings get a bit stronger, and then repot the whole seedling-pot directly in open ( well prepared) ground in autumn, without any root disturbance. For such big adult plants, I have long found that many 1/2 years seedlings of different genera/family generally do better when quickly put in the ground ( preferably in a dedicated multiplication bed, where they can still be watched closely).
I'll tell in a few weeks what will be the result of my last-year nobile-seedlings. Hope there will be something to tell!
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I think all mine must have germinated by now. There are 12 seedlings, none as yet with second, true leaves. I'm thinking it may be a good idea to pot each one separately now, before the roots become too long. I have no garden place suitable to plant them out so will have to keep them potted for at least a year. I'm thinking of a mixture of humus, gravel and grit as a possibly suitable mixture.
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Update 2012
2 rheum nobile planted last fall in their final place.
4 others were planted in the propagation bed, so that they don't have to spend the winter unsheltered in plastic pots.
The result for this spring is really encouraging for the moment, with only one loss, one which was planted in the propagation bed.
The 3 others went quickly also in the himalayan bed 2/3 weeks ago, on their final place too, as I didn't want them to settle down possibly too firmly in the propagation bed, what could have been later rather more a difficult and hazardous extraction than a transplantation ( no idea how quick and how deep does the main root grow, but didn't want to take the risk of waiting longer)
Just as info, I didn't find any thick or long root on the 3 I put out of the propagation bed.
[attach=1]
[attach=2]
[attach=3]
[attach=4]
[attach=5]
As you see, no huge difference for the moment between the 2 plants planted last fall ( pics 3/4), and the others transplanted for about 15 days. Transplantation was no stress ( well I took care of not touching any root).
However, all are still very small, the biggest leave of the strongest not reaching over 3 cms, and therefore still very vulnerable to every kind of possible threat ( possibly slugs?, heat, hail, underground mices).
But they are for the moment probably the most after cared plants of the garden, with every possible attention and surveillance from me.
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I'm really pleased to see your little Rheums Philippe. Mine are all potted and like you, there has been just one loss. I was thinking a few days ago that maybe they all were going to die because their greenery is going yellow and brown and dying away. However, I think now this is just winter coming along and I hope to see them again about August/September. That's the difference between sowing in autumn in the SH and in spring in the NH. Some plants sown in autumn even though deciduous by nature, will come through the first, newly germinated winter growing well but others, and this seems to be one, die off at the time they normally would. That is my hope anyway. Their compost is largely humus and grit/gravel and they're standing on gravel so should drain well. No decisions yet about where to plant them out.
Yours look great and I wish them very well. :)
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The Rheum nobile have grown since last time and look quite healthy, having been favoured by the almost constantly fresh and wet weather ( most of the time 10/15°C by day when cloudy/rainy, up to 20/23°C on the rare sunny days)
Growth is slow, with 2 new leaves for each one, the first appeared during spring having only slightly increased in size meanwhile ( up to 4/5cm for the greatest ones)
As you will notice, it looks like as if 2 different kinds of plants were developing: 2 of them with clear green and somehow pointed leaves, and the others with rather leathery more rounded leaves of a darker green ( I really suspect R.alexandrae for the former lot, what would really be a pity).
As both seed lots are wild collected ( on 2 different occasions/places though), I wonder if there wouldn't be an identification mistake somewhere for one of them ( would be curious?!), or if R.nobile can be so variable in leaf shape/colour at such an early stage.
[attach=1]
[attach=2]
[attach=3]
[attach=4]
[attach=5]
( pics of each rheum sorted the same way as in the previous post)
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On 12-06-2012 I saw in China at 4500 m young plants(see picture) and on about 400 mthere were a lot of plants in water so very wet. At that time there was o bud of flower in the plants.
I have got one plant 1 year ago and this plant grows very well but ubder rather wet condition.
Ton
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This plant immediately above looks very like Rheum delavayi. What do you think? Mine grows to just about 3 or 4 cms in height in leaf and the flower grows to maybe 10cms.
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Yesterday I noticed in the vegetable garden, the fat round blobs of rhubard breaking through their winter black stuff so I trotted over to look at R. nobile and every one (13) has a tiny green leaf appearing, a great relief as they were so small when they died back for winter. In another 6 or 8 months Philippe, mine should be as big as yours and I hope thriving so well. :D
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I had the wrong picture. At the top of mountain Shika Shan I saw the R. delavayi and lower the R. alexandrae.
Ton
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A lovely picture of R. delavayi all the same, beautifully coloured and marked. Mine is just beginning to show through - thankfully.
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Yesterday I noticed in the vegetable garden, the fat round blobs of rhubard breaking through their winter black stuff so I trotted over to look at R. nobile and every one (13) has a tiny green leaf appearing, a great relief as they were so small when they died back for winter. In another 6 or 8 months Philippe, mine should be as big as yours and I hope thriving so well. :D
Hi Lesley
Great that all your R.nobile made it through winter! It's such an excitement to see that new tiny pointed green spot looking out of the seemingly dead stems in spring, I remember of mines in May, how deeply happy I was then to see that life coming again. I wish yours all the best now and I suppose that if they find the weather to their taste in the next months by you and through your careful attention to them, they should be even bigger than mines by the end of the growing season.
Don't forget the pics Lesley!
I might post a last update of mines by the end of august.
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(http://ogorodnik.in.ua/images/plant/rheum_8.jpg)
I have just found this pic. An encouraging sight, as one can see that Rheum nobile not only grows in unreachable/cold heights, but for example here just a few hundred meters above tree-line, on what seems to be quite a sunny slope.
The cool root-run is nevertheless guaranteed with this layer of beautiful stones ( wish I had them to put in the beds :-\ )
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A spectacular photograph - both the plants and the scene 8)
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At present we live at 300 metres above sea level and quite close to the coast so the tolerance levels of my little plants will be tested to the full. When we move, whenever that is, it is most likely the altitude will me much less. I may have to obtain a dedicated refrigerator or perhaps send my plants to live with others whose conditions better suit it. That would be a shame as this is one of my "holy grail" plants. ???
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Why the hell there is no alpine garden in NewZealand south Island??? There isn't anyone, isn't it?
I am pretty sure miracles would be achieved there too ::)
Here my last update of the year about the rheum nobile I think. Results are really encouraging, more than ever, I now strongly hope that the next winter will be rheum_nobile_friendly ( 4/5 months snow cover), to help the plants to settle down further and become stronger for next summer.
I put out the 2 rheum which will very most probably be R.alexandrae, and kept the 3 hopefully true nobile.
[attachimg=1]
[attachimg=2]
[attachimg=3]
As you see, the lower leaves begin to get yellow/brown, and I really like the fact that a last new healthy leave is emerging in each rosette of the 3 rheum. I don't know why, but somehow I think the roots are now deep and strong enough to sustain new growth even so late in the season, having the possibility at the same time to let the older leaves die down, as if they were not absolutely necessary for the plant.
I can't explain it really, but again, I really appreciate that sign.
I may be wrong also. I decide to be optimistic though :D
A new patch of potted seedlings is waiting in the propagation area, but they will surely not be planted out this year, or I must rapidly find place for some of them at least.
I am tempted to plant out the 2 pseudo nobile/alexandrae to install 2 further true nobile at that place, but well...
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Philippe, there are many alpine gardens in the South Island, or perhaps it would be more accurate to call them rock gardens as almost all - these are private gardens of rock/alpine gardeners - are coastal or nearly so and far from the higher reaches of the mountain areas. Certainly the Dunedin Botanic Garden has a very good public rock garden and I'm not sure what there is in Christchurch nowadays. At least one NZAGS member lives at Wanaka among the southern lakes and mountains and would perhaps be in the best position to have a garden such as I think you may have in mind.
Unfortunately there is never likely to be any kind of true alpine garden in the alpine regions as those interested in native plants are determined on the exclusion of OTHER than native plants. I can imagine that some of our native growers who spend time in the mountains would be utterly horrified at the though of a Rheum, an Androsace or Saxifraga making its way into our alpine regions. They are totally obsessed with keeping New Zealand's flora exclusive. There have been good lessons of course, such as gorse and old man's beard but even so, there would be no support from anyone, I should think, for a public or commercial alpine garden in those parts of the country where it would best succeed.
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It's a huge pleasure to begin the Rheum nobile observations again in 2013. The 2 years seedlings that were planted in the himalayan bed are actually all 3 still here.
There was a bit of fear right after snowmelt as the little plants were difficult to locate without any sign of new growth, but after some days of exposition to air and light, the first new leave soon appeared on each seedling.
The most advanced of the three is already about to unfold its second leave, although it wasn't the first to get out of the snowcover.
They seem to be now firmly anchored in the soil, they almost didn't move sidewards anymore when I gently pushed them to test their "solidity".
[attachimg=1]
[attachimg=2]
[attachimg=3]
Another 1 year seedling from another sowing was planted in the same bed during fall last year, and looks presently pretty happy too. It will probably join the next update then.
The rest of the same sowing, 7 plants, spent the winter in individual pots on the propagation area.
The snow has just melted there for 3 days, but a new pointed red leave is already appearing on some of them, another very encouraging result.
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One month later, with some warmer days in between, particularly in the last 2 weeks, the Rheum nobile show quite steady growth now.
Here the last pics from today:
[attachimg=1]
[attachimg=2]
[attachimg=3]
[attachimg=4]
The first three are always the same as last times ( I think each time put in the same ordrer in the previous posts), and the last one is new to the update.
Again some difference between it and the first other three. A different collection, but it looks like it isn't going to be R.alexandrae this time, the leaf blade is quite different. But I find this bright green strange, in regard to the more reddish colour of the others.
We'll maybe see what it will be later.
The bigger leaves on the strongest plant ( the third one) are about to reach already the 5 cms length mark. I suspect the summer growth will reserve surprises in the next weeks.
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This Rheum alexandre is from AGS seed in 2010. I hope it will bloom next year. It's been hardly any problems. But I think Rheum nobile is more difficult.
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Time again for a little look at the Rheum nobile in the garden.
[attachimg=1]
[attachimg=2]
[attachimg=3]
The first one is the weakest one. It didn't grow that well I find. Things started right untill late June, when warmth and drought came together to give us one of the "prettiest" summer of the last decade. Maybe this plant in particular didn't appreciate the weather, and choose not to grow further?
The second one is already a stronger plant, situated just 1 meter away from the first one. This is reassuring as it means Rheum nobile can reasonnably still cope with what was a too warm and too dry summer here, a thing we hopefully should not have every year.
The third gave the greatest hopes of the season. It might be because of its position above a dyke in which runs a streamlet, providing sufficient air and perhaps also soil humidity, but it's the prettiest one. The biggest leaves were about 10cms long.
I am really sad to say that I have lost the 6 individually potted seedlings that grew on again at the season's beginning. I suspect that at this vulnerable stage the warmth combinated to too much watering in the propagation bed, and not enough air movement because of almost constant shading brought them later to die in July. These were sadly 6 true Rheum nobile as far as I could see from the leaf.
All the rest that had been planted in the garden last year or so will be R.alexandrae. From diverse sources. A shame that one can make the mistake on such an inimitable species when collecting seeds in the wild ( apart from the very different habit of the plant, I guess R.nobile wouldn't grow happily where R.alexandrae grows).
Next update next year then, with good news I hope!
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Amazing Philippe. You put us all to shame, these are very healthy Rheums.
johnw - another brilliant day to 22c
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Searching for information on particular plants, I often end up referred to SRGC pages- of course, who is growing some of these odd plants if not SRGC members?
I happen to have R alexandrae seed now, just wondering if it needs any special germination treatment? Still web searching, but hadn't found anything yet... and it sounds like if I get seedlings, they are not too fusssy, but want to be moist?
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Definitely, R. nobile is more difficult to grow (I've lost all of mine in their 2nd year) and, according to Harry Jans, IMPOSSIBLE to flower in cultivation. I guess Phillipe may be the closest any of us has gone to that amazing event. :D
Most Rheum seeds seem very quick and easy to germinate and most seem OK to grow on but a few present more difficulties. I didn't get any germination from R. tartaricum and only a couple of seedlings from alexandrae. R. nobile germinates well - 100% - but the problems start after that. Of course it is a wet scree plant rather than a boggy plant like some. My most favourite of all is the tiny R. delavayi, just about 15cms high in flower and making little tight mats of 3-5cms wide foliage, deeply veined and reddish. It always comes through rather late for me after winter dormancy and I always fear I've lost it. Only had seed a couple of times and not recently. I think it too, doesn't like a bog but prefers a moist but very well drained place. Mine has been in a raised bed for most of its life, but currently still in its moving pot. Compare its size with the little "juliana" type primrose beside it. :)
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Your R. delavayi is charming, Lesley. I hope mine look like that one day.
Rheum rhizostachyum has survived here as well. Here it is in seed:
[attach=1]
(P.S. Ignore the big weed in the upper left corner of the photo... was supposed to be Saussurea napalensis but turned out to be some meter-tall Picris(?). I was just waiting to see the flowers, towards an ID before I yanked it out. ::))
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cohan, Rheum alexandre also germinates fairly quickly and does not require cold stratification. The substrate should be slightly moist, but not wet! In the second year you should they can plant outdoors. Give them a cool and bright place. For me, they suffer in the summer under the heat. Your temperatures are likely to be better.
Lesley and Lori, what interesting plants are your Rheum!
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Yours is gorgeous Lori. I don't know that name at all. I think there are a number of quite dwarf rheums which are very attractive but not at all common - or generally available, unfortunately. I once had R. ribes of which there is a super photo in the Phillipa and Rix "Perennials" book. It didn't stay with me long enough to flower though and can't be got here in NZ. And R. spiciforme was quite happy with me for several years and did flower for two, then vanished one winter, or rather, didn't reappear in the spring so maybe rotted.
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Thanks for the input, ebbie and Lesley! How wet does alexandrae need to be once in ground?
Lesley- delavayi is very charming for sure- I've seen pics before, and it is very desirable :)
Lori- another cool species- how tall is that one? Was that from Czech seed?
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Hi Cohan
Just came upon this thread again. Nothing to update with R.nobile though. R.alexandrae seems to enjoy a very moist soil, with good/reasonable drainage however. Some plants grow nearby a streamlet in the alpine garden. Not directly at the water, but maybe 1 meter away, and not really much higher than the water level. Of course there is no water in the ground at this place, but the soil never never dries out.
So I guess they really love a generous water supply throughout the growth period.
And the fact that the plants look thirsty as soon as the sun is too strong for a few days, coupled with warm temperatures, is a clue to what their favourite diet is: moist/quite fresh/quite cloudy ;)
However they are strong plants in the general climate here, and they don't get the same care as R.nobile, by far not!
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Rheum rhizostachyum is smallish but not near so small as R. delavayi appears to be. The leaves have gotten to about 20 cm max so far (usually only 3-4 leaves present). It's bloomed in 2 consecutive seasons now, with flower stems elongating this past season to about 25 cm in seed.
I grew it from seed in 2010, so I don't have a great deal of history with it! Seeds were from V. Holubec, collected in 2006 in Tajikistan, Yazgulem Range, Pamir, at 3800m in gneiss scree, and described as "caespitose perennial plant; 2 ovate ground leaves, 15 cm long, flowering spikes 15cm long, red prominent fruits".
As was said, I found too that Rheum delavayi, R. rhizostachyum and R. alexandrae germinated at room temperature within a few days, without needing stratification. I grew R. alexandrae years ago, not in rock garden conditions, and didn't get it to flowering. Perhaps it would have a better chance now that I probably have more suitable places to plant it.
I have Phillips and Rix's "Perennials" too, Lesley, and used to make long lists of what I hoped to get from the photos there! Rheum ribes would be one of those!
Enviable results, Ebbie, and especially, Philippe!
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R.alexandrae seems to enjoy a very moist soil, with good/reasonable drainage however. Some plants grow nearby a streamlet in the alpine garden. Not directly at the water, but maybe 1 meter away, and not really much higher than the water level. Of course there is no water in the ground at this place, but the soil never never dries out.
So I guess they really love a generous water supply throughout the growth period.
And the fact that the plants look thirsty as soon as the sun is too strong for a few days, coupled with warm temperatures, is a clue to what their favourite diet is: moist/quite fresh/quite cloudy ;)
Yes Philippe, I agree. For me, the plants are located next to a small garden pond. I think that the humidity in the air is important, too. On the other hand, the root at a plant that was too close to the pond, rotted away.
I am curious if my plants this year will come to blossom.
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Thanks for the additional details, Lori, Philippe and Ebbie. If I get more than one seedling, I'll probably try a couple of different spots. I don't have any ponds or streams, but I do have below grade areas between ridges of rock garden and berm, north sides of those raised areas that stay cool and more or less moist, so it will probably be a spot like that- not right at the bottom where it may be too heavy, but a bit above where the soil should stay cool and moist.
The issue of plants wilting is interesting to me- I have a few species that wilt on any slightly warm, sunny day, even with moisture still in the soil, and some humidity in the air...yet they are not full shade plants, I think. I'm gradually trying to move them to spots where the roots and crown are cool and shaded (again, north slopes, or behind rocks/wood)..
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First update 2014
All 3 true Rheum nobile are still here, despite the last-not-really-winter.
It's funny to see how every June 2014 Rheum looks almost perfectly similar to what it looked in the update of June 2013: same number, disposition and proportions of leaves. Everything nearly the same, but the plants are only on the whole bigger.
First one is still smallish, as it did last year. It produced so far 3 to 4 new leaves, but they are small, not more than 3/4cm. It might stay a weaker plant for ever, and I wouldn't be surprised not seing it come again in one of the next springs.
[attachimg=1]
Second one becomes an interesting plant, with the central nerves getting white and larger now, as does the stem. The leaf shown in the pic is about 8/9cm now.
[attachimg=2]
The last produced 3 big leaves already this spring, reaching 8/9 cm here too. As last year still the most promising of all 3.
[attachimg=3]
I don't dare to say that the last 2 rheums are on the way to get adult, and have passed what should be the hardest and most dangerous part of their childhood, but if there is no critical event meanwhile ( a very very bad winter/summer, or deadly damages on the roots by rodents), they are "teenagers" now, and seem to be able to cope with the normal climate here, and I want them to flower in some years.
Every other not happy ending story is not allowed, it's gone too far now ;)
I just wonder how do the flowering plants behave. I think Rheum alexandrae is not really self fertile, and the first time I could harvest seeds on it was when 2 different plants flowered at the same time last year.
I hope Rheum nobile sees things a bit different, then it would be more than providential if 2 of the 3 cultivated plantswould come to flower at the same time. If they ever get to that stage of course.
I didn't see seeds in lists these last 2 years. The best would be to have, of course, euh let's say...about 15/20 Rheum nobile on different stages in the rock bed ;)
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A last look at Rheum nobile for this season 2014.
Recently I had to plant out the weakest of the 3. It just didn't progress this year, and I wanted to understand what was wrong before risking losing it. May it be the soil mix or whatever, but the main taproot was broken or rotten a few centimeters under the collar, so that the plant only survived with some lateral secundary roots born above. It was planted in another place meanwhile, with new soil, to see if it can get a new chance.
The other 2 begin to get impressive plants. Partly because they are Rheum nobile I guess, because every other more common rhubarb species would still be called smallish at that stage...
[attachimg=1]
[attachimg=2]
The very wet and fresh weather we had nearly during the whole 2 months July and August with many days in fog really pleased them.
Let's hope they now get a good winter.
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Well done Philippe. VERY well done. They certainly ARE impressive. I wish you whatever kind of autumn/winter will suit them best, and look forward to hearing good news in the spring. :)
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Update 2015.
First of all, one pic.
[attachimg=1]
I really don't know what to think of it...I know garden and plants always look awful at the very beginning of the new seasons, but I really have doubts this year about Rheum nobile...Both plants look similar for the moment, and the third one, the weakest one I wanted to save last year, seems to have disappear meanwhile.
Rhubarbs in general here are often notorious for showing almost immediately the new red shoots pointing as soon as the snow has melted. So did untill now Rheum nobile too.
At that place where the nobile are planted, the snow is away since 2 or 3 weeks at least, and there have been some really mild days meanwhile. So still no new shoots? I fear the worst... I guess I'll be sure if there's no change in 2 weeks!
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Here they are again, both Rheum nobile!
Actually, the emerging new red leave just appeared on both plants only 3/4 days after I took the first picture.
I gave for the first time a slight hint of fertilizer, in form of roasted horn powder.
I got some seeds from last winter exchanges ( hopefully they are true), and will sow a part this spring, and probably next year, and so on, in order to have if possible plants from all ages, to compense the monocarpic habit of the species ( I already see so far ;) ).
So place to the stars now!
[attachimg=1]
[attachimg=2]
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Philippe,
Jim Jermyn describes in his book The Himalayan Garden his experience
with the cultivation of Rheum nobile. Maybe it is useful for you.
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Hi Rudi
That book laid a long time on my nightstand, and I feel it's time to read it once again soon, for all the magic that's inside, for all the superb pics and advices and for all the rest.
I had it perfectly in mind when I began the Rheum nobile journey with the first plantation in the bed some 3/4 years ago now: cool rootrun amongst rocks, drained mix, and ample humidity. That works pretty well for the moment it seems, but of course this all is made much easier by the mountain climate of the alpine garden.
Another 2 or 3 years without problems, and maybe I would almost find Rheum nobile not particularly difficult to grow here, once its climatic requirements are satisfied. I have far more problems with Ranunculus glacialis that I can never get much further than the simple surviving stage, Campanula cenisia ( which I lost last winter) or Eritrichium nanum for example.
For the moment, there's clearly something much easier and much more peaceful about Rheum nobile cultivation, in regard with all these other plants that yet come from much nearer.
Hopefully this lasts a while!
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Number 1
[attachimg=1]
And number 2
[attachimg=2]
Both Rheum seem now to be in a hurry to produce new leaves. The second one is going on its third leave after only 3 weeks of growth, and the first two leaves were already quite big, for first leaves at least ( 4/5cm length).
They have a complete season now to strenghten a bit more, so come on!
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"The high altitude rhubarb from China, Rheum alexandrae flowering at the pond in the rock garden at "The Botanics" ( Royal Botanic Garden Edinburgh)"
Photo from twitter by John Mitchell
[attachimg=1]
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That is absolutely stunning. Mine has never flowered, just stays quite small - may have to look for another place for it.
Susan
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Beautiful Rheum alexandrae! This is such a presence in the rockbed when the flowering stems are getting higher.
It is also flowering at the Haut Chitelet now.
And the brother nobile nearby is making huuuuge ( in my opinion) leaves right now. Update should follow in the next days ;)
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June update
Hailed Rheum nobile though :-\
A thunderstorm hit last week-end. Not a disaster, but plants with larger leaves suffered a bit.
So, this means that Rheum nobile now truly deserves the word "larger" for its leaves ;) New ones will follow anyway.
First plant:
[attachimg=1]
Second one:
[attachimg=2]
It might be not obvious on the pic, but the biggest leave on first plant reaches 20cm, and is hiding almost entirely one Corydalis cashmeriana in the background, which will have to live with an invading neighbour from now on ;) I'm not sure it will get enough light next year if Rheum nobile goes on growing like it does now. Well, pleasant problems, let's say.
A look at Rheum alexandrae just nearby. Encouraging his brother to do [attachimg=3]the same way one day?
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They're looking very hopeful Philippe. Wonder how long it takes to flower - if it ever does? It will deserve a cake to be baked. ;D
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At least a cake Lesley, at least ...
Despite heat, despite drought, Rheum nobile are healthy
[attachimg=1]
[attachimg=2]
Of course they're watered regularly, and shaded during the days of fierce sunshine, which is almost everyday since 3 weeks now.
But untill now they are admirably withstanding the exceptionnal weather conditions.
Probably the setting helps a lot, planted on the north slope of the bed, where the sun only shines untill 2 or 3 PM, which prevents somehow the overheating of stones around during all day.
Note they were photographed with a wide angle lens, as they don't fit anymore in a more focused lens ;)
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Here a last look at the 2 Rheum nobile.
[attachimg=1]
[attachimg=2]
Number 1 has a worrying look. It grew well untill mid-summer or so, then stopped normal growth, making leaves always smaller as the weeks went by, so that the growing period last leaves are the smallest one of all :-[
Really don't like the colour of the plants. Would be ok if it looked this way now, but so it was already from mid-august on. Something clearly going wrong with that particular plant.
Maybe a weaker plant that suffered from the tough summer, even though frequently shaded and watered, starting to try to go dormant with the repeated heatwaves, as do some of the more sensitive monsoon himalayan plants?
Because of the colouring of all leaves early in the season and their decreasing size, I fear also a problem at the roots ( rot or anything else reducing the root amount), which could unfortunately be comprimising for the seasons to come. I would not be surprised not to see him shoot again next spring, or really going down next season.
Number 2 is a world apart from number 1. Healthy and numerous large leaves, only the first ones from spring turning yellow now.
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2016 updates!
As expected, Rheum nobile number 1 has given up. No growth this year, how sad.
Number 2 however is still alive and shooting its first new leaves :
[attachimg=1]
The update can"t be that interesting with just one plant, doesn't it?
I hope adding new younger R.nobile to the observations in the seasons to come: some seedling growing in pots in the propagation area.
But as always, a crucial and difficult stage in the life of Rheum nobile: pot cultivation...
Next stage then will be to check if these are going to be true R.nobile or again R.alexandrae, like last time. For this, it will take several further weeks, untill leaves take more texture/shape and colour to get clues on possible identity. Might also be possible next year only.
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Looking good so far Philippe. :) When I've had seedlings of R. alexandrae they have always been totally green and flat-leaved, right from the start so yours with its colouring does suggest it will be nobile. Let's hope for that.
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Hi Lesley
Yes, the bigger plant in the bed might be Rheum nobile ( and now that one of both has suddenly gone, it only conforts me in the fact that it might be indeed the more tricky R.nobile ;) )
When talking about R.alexandrae, I meant the young seedlings I still have in pots in the propagation area. They're still way too small to decide 100% whether nobile/alexandrae or not, even if by now, I rather suspect they could actually be nobile. Let's see in several weeks!
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[attachimg=1]
Another good summer season it seems for the surviving nobile who looks very healthy by now.
I find it a bit leafy/leggy but anyway, it still lives!
Pot cultivation has been fatal to one of the young seedlings. Pricked out in June, everything seemed ok, 2 new small leaves, and within one week recently, game over.
Another had been planted directly in the Himalaya bed in June, and it resisted so far.
2 further seedlings from last year were pricked out today, but this time directly in the pure sand bed, where any water excess will freely find its way down.
Another 2016 sowing pot with 3 other very young seedlings in waiting for prick out, and then that will be all for R.nobile for the moment, as the seed stock has been totally used now!
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(Attachment Link)
2 further seedlings from last year were pricked out today, but this time directly in the pure sand bed, where any water excess will freely find its way down.
Another 2016 sowing pot with 3 other very young seedlings in waiting for prick out, and then that will be all for R.nobile for the moment, as the seed stock has been totally used now!
Well done, I think I have again killed further young R.nobile seedling this summer. DOn't know why it won't work this year.
The ones that were pricked out directly in the sandbed during late July have also gone now.
They did reasonnably well meanwhile, even letting a new small leaf emerge, but for each one, on a week interval or so, that young leaf became very soft, and that was it for the whole plant. No watering problem, no sun scorch. What then...
The 3 last remaining ones will stay in the sowing pot now. They'll have to bring it through next winter then ;/ And I even wonder if they won't be planted together at the same place in the rockbed next spring, if they're still alive of course, without any pricking out operation before.
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Last update on Rheum nobile.
Very recently photographed with a wide angle lens, as its size makes it now possible to spot it effortless in its environment ;)
[attachimg=1]
The young seedling planted in the bed in June made it through the first summer. He is rather fine right now I would say.
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It looks like a very happy rhubarb Philippe. I hope you'll find it in good health next spring coming!
The background of your picture resembles very much with an impressionist painting.
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It looks like a very happy rhubarb Philippe. I hope you'll find it in good health next spring coming!
The background of your picture resembles very much with an impressionist painting.
That shrub in the background is a delight, particularly when it's turning red in autumn.
Not the right thread to post a picture of it, but I love it so much ;) :
[attachimg=1]
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That shrub in the background is a delight, particularly when it's turning red in autumn.
Not the right thread to post a picture of it, but I love it so much ;) :
(Attachment Link)
Really an eye candy, your image. I am always very impressed. You have a very great talent when photographed...and of course in the garden. :)
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That shrub in the background is a delight, particularly when it's turning red in autumn.
Not the right thread to post a picture of it, but I love it so much ;) :
(Attachment Link)
The right light, the right moment and someone there to take the picture ;)
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Bringing this thread back to the top.
I made no update last year. The Rheum nobile just continued on getting stronger.
Right now, it is just sprouting out of the soil again, not without having given the usual fears before: no sign of new growth during the last 2/3 weeks, although the weather was fine and not so cold and snow had gone since mid-late April.
But here he is again:
[attachimg=1]
I think I can see some translucent part on the emerging leaves in the very middle of the plant. I wondered if this could not be the bracts of a oncoming flowering stem? Not sure though :
- I firstly would have expected a much larger bud if a blossom is expected in the next weeks ( or it may be the plant will only produce a very weak flowering stem)
- the plant still looks not mature enough for me to have already reached flowering stage.
Let's see. The plant development is very fast once it is awoken from the wintersleep, I'll know more probably next week already ;)
Edit 01.06: no flower for Rheum nobile this year ;)
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The emerging Rheum nobile enjoyed the wet and very mild weather we had during the last weeks. It litteraly exploded within the last 15 days and here is how it looks now :
[attachimg=1]
Found this article on Rheum nobile flowering particularities and adaptation to the high alpine climate :
http://english.kib.cas.cn/rh/rp/201211/t20121108_95047.html (http://english.kib.cas.cn/rh/rp/201211/t20121108_95047.html)
As a gardener, and as many others here I guess, I had to wince reading some lines and seeing the pictures, especially the one lettered with "e": taking away the bracts to measure their role/efficiency in the seed production process ! It just hurts!
Science, science :P
I'm sure they did'nt even do anything with the seedlings after the germination tests. Probably the pots were thrown away, as this is no protected plant. That hurts too!
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I have just read through this post, and it seems that the fun has only just begun. Seed sown 17 January 2019.
[attach=1]
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That was fast Keith.
If only the seedlings/young plants would be so easy going! Good luck with it.