Rhodothamnus

[Maggi Young]

 While planted on peat sand three pots, one left at +20, the other exposed in the street, and the third seed handled gibberellins and I will keep it at 0 - +10 ° C:)

well Natalia, you are certainly making every effort to make these seeds happy.... good luck!

 Franz Hadcek has a great photo of this plant growing in a trough in his Vienna garden : http://www.franz-alpines.org/

[Natalia]

Maggi, thank you for your good wishes.
 It is these photos, like Franz Hadacek and move on Rhodothamnus growing from seed:)

[hadacekf]

Easiest from seed, fresh if possible. It may take a long time to germinate, and as it is slow-growing it may even be two years before it is large enough to handle.
I always lost my seedlings after two years. My plant was collected as a seedling before 30 years.

[johnw]

My little V. praestans (12) are getting a red shading too. Are they deciduous? They're about 5cms across now.

Lesley - V. praestans is completely deciduous here.  Last year - 2010 - it flowered twice and fruited twice.  It can be quite thuggish in peaty soil though never more than 7cm tall.  Once you get it going you can easily just yank a piece out, pot it up and give to friends; few if any fail. Brilliant autumn colour in full sun.

I have never been able to keep a seed grown Diapensia purpurea alive past the speck of dust phase - a phase that lasts quite some time.  Do tell us how.

johnw

[johnw]

Easiest from seed, fresh if possible. It may take a long time to germinate, and as it is slow-growing it may even be two years before it is large enough to handle.
I always lost my seedlings after two years. My plant was collected as a seedling before 30 years.

Franz - Have you tried cuttings?  I think Baldassare at Siskyou Rare Plants told us to take them when very soft.  My plant came from him & grows in a trough.   It does not like snowless cold winters and is by no means not up to your standards!  A few flowers every year but never covered in them.

johnw

[Maggi Young]

I remember John Good's ( Wales)  lovely plant of Rhodothamnus chamaecistus  which won the medals at the show at the Alpines International Conference in Warwick in 1991... a beauty.
In Scotland Lyn Bezzant counselled that she cut hers up with a bread knife every ten years or so to split it up.... mine has never  grown large enough to even tempt me to try this! 

[Lesley Cox]

I had in mind that my Rhodothamnus seed was from SRGC but having just looked at the label (if all else fails read the instructions...) I see it came from Thomas Huber who shares seed he has been given so I think it may well be from either Franz himself or possibly the late Hans Hoeller.

The Diapensia came as a well established plant from a local (Christchurch) source, someone who produces some very fine species at a stall at NZAGS annual Sept show. It must have been maybe 5 years ago and it has been in my quite shaded tunnel ever since but recently I took the Diapensia by the horns and planted it outside in the corner of a trough which gets about half a day's shade and which, for now at least, I'm covering from the afternoon sun until the roots get well down. There are ramondas and small, choice primulas in the same trough and my most treasured frit, 2 bulbs. So I've not tried it from seed. Actually, I did get seed from AGS way back but nothing ever germinated. It had been collected in Japan I think.

Thought I'd better produce some proof of the pudding.

First the Diapensia then two of the Rhodothamnus. There are 7 seedlings, 3, 2 and 2 and possibly an 8th but not sure, might be something else. They are about 2mm wide and 3mm high.

[Natalia]

Franz, unfortunately I do not know whether or not fresh seeds. I got them only in January ...
 Have you lost your seedlings because of transplantation or after winter?

 Maggi, very interesting! But to me such a radical way is still very far

Lesley - Rhodothamnus plants are small, but happy life:) Czech collectors write that for the development of Rhodothamnus requires acid soils with limestone bottom.

 I join request John - tell, how it was possible to grow up Diapensia purpurea?

[johnw]

Czech collectors write that for the development of Rhodothamnus requires acid soils with limestone bottom.

Natalia - Many Rhododendron species grow in just such acid soil above limestone but none require anything but acid soil.  Perhaps the underlying limestone suggest excellent drainage beneath.    R. schlippenbachii is the only species I can think of that likes a bit of lime to snap it out of slow growth, sometime a bit for ferrugineum & hirsutum too. So.....

Lesley - I have never seen such long shoots on a Diapensia lapponica, here it barely manages 1/4 inch. Japanese form? Any shots of it before it flushed?

johnw - +2c

[Natalia]

John, there are other kinds of rhododendrons, which need the presence of calcium in acidic soils. In Siberia - Rhododendron adamsii - grows only on the calcium-rocks, mainly limestone.

Yes, rhododendrons require acid soil, but do not confuse the soil pH and calcium content in it, it's different.

 But the Czech Republic on the recommendation alpinaristov Rhodothamnus chamaecistus - you probably know Rock Garden Plants Database - http://www.kadel.cz/flora/d/kvCard.asp-Id=2121.tm

[ian mcenery]

Natalia here is a picture of Rhodothamnus growing in the dolomites. Strange as it grows both in the scree in full sun as well on north facing sites. This one was south west facing on a scree that must have had moisture running underneath as it was quite hot. I grow it in a trough and it is now about 25cm in diameter but doesn't manage to flower like Franz's. I am trying to germinate seed in dried sphagnum moss and we will see. With Lesley's success it seems many methods will work providing the right level of moisture can be provided at the right time

[ian mcenery]

John I have been growing Diapensia lapponica for about 4 years now and it increases steadily but does not flower. How do you manage yours? Mine is indirect light (not shady) but very cool. Does it need sun it must get more summer light than I can provide

[Natalia]

Ian, thanks for photo Rhodothamnus in its habitat.
 I will necessarily consider that it the lover of dolomitic taluses.

[johnw]

Natalia - Thanks for the tip on adamsii.  The soils on our coast are sometimes very acidic so not unusual for us to have to add lime to release nitrogen and add a bit of locked up calcium and magnesium too. Magnesium deficiency is especially common, friends inland with better soils have no such problems. Might be time to give my Rhodothamnus a pinch. It is quite amazing how quickly a slow schlippenbachii reacts to a handful of bonemeal thrown its way.

Have you tried your native Rhododendron fragrans?  I had several seedlings from either Halda's or Mrs. Berkutenko's seedlists. They were extremely slow-growing. Unfortunately I put them outdoors in full sun with a shade screen over them, several days later I took the screen off, went indoors and forgot to replace the shade. They incinerated and have never seen seed offered since.

Ian - I do basically nothing but water the Diapensias, especially important when the humidity drops in August/September. Rarely they might get an accidental splash of water soluble. The root system is in heavy soil at the bottom of the trough but the necks of the Diapensias are mainly in gravel, this is as I saw them growing in Newfoundland. One year I got a flower every month of the year save January/February. Only one year did 2-3 flowers open simultaneously, seed pods usually abort.

johnw

[Natalia]

  John, I tried to sow the seeds of Rh.adamsii Berkutenko and seeds from another source (collected in expedition). Unfortunately, in both cases, seeds were old: in the first case - has ascended a zero, in the second - has sprouted two seeds, but throw off a skin they could not. 
 This year, sowed the seeds obtained from the Czech collectors - hopefully germinate, 1-2 began to sprout.

 If also it does not turn out - it is necessary to go to Sayan mountains and to collect seeds. 

I regret for your loss - with Rh.adamsii just as with Rh. redowskianum - it is very difficult.

And a little about Diapensia lapponica - that's how she likes to grow in our Hibiny.