Rhododendrons 2014

[Maggi Young]

It's habit is nice and compact.

 Magic words - the opposite is true of so many plants with good flowers, isn't it?

[Robert]

Maggi

I like growing Maddenia rhododendrons. What can I say, some can be so unruly. It's nice for me when something turns out... smaller, compact.  The real issue is that I'm always running out of space for creative projects. Growing smaller plants seems to be the solution, but then sometimes I like that leggy 'Salvidor Dali' look.

Robert

[Lesley Cox]

Super rhodos Uvularia but tell me a little more about the Sorbus. Is it a very dwarf - though large leaved - plant or have you picked a stem with fruit to photograph? The fruit and the leaf colour look amazing.

[Roma]

Those of you who have not yet done so click on the link to Uvularia's website and under News look for 'No Whiteys Since Kingdon Ward'.  You will find a most interesting account by Nick Macer of the expedition to Manipur with wonderful photographs.

[Steve Garvie]

Rhododendron dauricum


This is always the first Rhodo to flower in my garden and usually the blooms get frosted. Rh dauricum has little to recommend it other than flowering when almost nothing else does. This plant has become leggy as it is somewhat shaded.

[Robert]

Our R. duaricum almost always get frosted too. I plant them here and there thoughout the garden so they create a purple haze when nothing much is blooming in the way of woody shrubs. Some have chocolate foliage in the winter that looks good against a golden back drop. This all works for me.

Right now, the R. dauricum finally have some color in the flower buds. Very strange since it has been 22 c or more during the day. This is record heat for us in January. Tuesday will be 45 consecutive days without rain or snow during the "rainy season" a new record, with no rain or snow in sight. Reminds me of Northern Europe in 1304.

Robert

[Thorkild Godsk]

Rhododendron.
3 Rhododendron I think there are lovely:
1-2 Rd. Xanthocodon
3 Rd Cinnabarinum ssp cinnabarinum Roylei
4 Azalea Jack Brydon
Kindly
Thorkild-DK

[Anne Repnow]

Wonderful, wonderful photos of gorgeous plants! Thank you!!

Here is one not very special rhodo, which I like for ist dark delicate leaves and early bloom: Rhododendron ponticum 'Graziella'

[Robert]

Thorkild,

Beautiful rhododendrons. The cinnabarinums are so nice. Wish that they were easier for us to grow here, however I keep trying.

I look forward to more of your lovely photographs.

[fixpix]

No Rhodos in my garden, but I can always admire pictures.
Thank you Thorkild & Robert!

[GordonT]

Rhododendron cinnabarinum didn't survive our winter here in 2012-13. After looking into it a bit more, I discovered an unusual feature of the plant- it produces toxic nectar- it is apparently fine for insects, but honey made from it contains grayanotoxin- not good for humans.

[Maggi Young]

I believe that many rhodos - perhaps all - have this "toxic" nectar, Robert.

This has been long reported :
 Xenophon in 401BC (Lampe, KF, 1988, J. Amer Med Assn 259: 2009):

'The number of bee hives was extraordinary, and all of the soldiers that ate of the honey combs lost their senses, vomited, and were affected with purging, and none of them was able to stand upright; such as had eaten only a little were like men greatly intoxicated, and such as had eaten much were like mad men and some like persons at the point of death. They lay upon the ground, in consequence, in great numbers, as if there had been a defeat; and there was general dejection. The next day, no one of them was found dead; and they recovered their senses .... '


and  more recently: Abdulkadir Gunduz, Suleyman Turedi, Hukum Uzun, Murat Topbas Mad honey poisoning. Amer J Emergency Medicine (2006) 24: 595-598

"Grayanotoxin intoxication, which is mostly seen in the eastern Black Sea region of Turkey, stems from the “mad honey” made by bees from the rhododendron plant flowers. In low doses, this causes dizziness, hypotension, and bradycardia, and in high doses, impaired consciousness, seizures, and atrioventricular block (AVB).

This case study was designed as a series of cases of patients (6 women, 2 men) aged between 35 and 75 years. All of the patients' physical examinations revealed hypotension; 4 patients had sinus bradycardia, 3 had nodal rhythm, and 1 had complete AVB. In all patients, except for the patient with AVB, heart rate and blood pressure returned to normal limits within 2 to 6 hours. Two patients were monitored in the coronary intensive care unit. Of these 2, 1 was discharged on the second day. The other was fitted with a temporary pacemaker and was discharged on the third day. All the other patients were kept in for a 6-hour observation period and were then discharged from the ED.

To date, 58 such cases have been reported, but we saw 8 patients within 2005. It is commonly seen in the east of the Black Sea region, although cases may occur from all over the eastern Black Sea region of Turkey. So far, no cases of death have been reported, although grayanotoxin causes adverse effects on the cardiovascular and respiratory systems and is therefore of considerable importance. "

Various  isolated reports of people suffering from a reaction to rhodo honey  can be found on the web - and the nectar can be harmful to bees as well it seems.

An Irish university was researching into this - but I have only found the introduction, not the finished papers : http://www.tcd.ie/Botany/research/stout/toxic%20nectar%20and%20pollen.php


Some info here : http://www.rhodyman.net/rhodytox.html

[johnw]

Thorkild  - I don't think #3 is 'Roylei'.    'Roylei' has a more slender flower and quite red.

johnw

[Robert]

Maggi,

I enjoyed some of the history of toxic honey. Some interesting books to look into. My wife and I go to the library once or twice a week. We have a fantastic library system so we rarely feel the need to buy a book. Thank you for sharing your research. 

[Anne Repnow]

I believe that many rhodos - perhaps all - have this "toxic" nectar, Robert.

Thank you, Maggi, that was most enlightening - didn't know that!