Rhododendron griersonianum
Balf.f. & Forrest
Ericaceae
Common Name:
General Information
Rhododendron griersonianum is an evergreen shrub with a lax, open habit; it can grow 1 - 3 metres tall[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
,
266- Title
- Flora of China
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/china/
- Publisher
- Missouri Botanical Garden Press; St. Louis.
- Year
- 1994
- ISBN
-
- Description
- An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
].
The plant is grown as an ornamental in gardens, where it can be used to form a hedge.
Known Hazards
Although no specific mention of toxicity has been seen for this species, all parts of Rhododendron species (including the leaves, flowers and pollen) contain greater or lesser amounts of the toxic compound andromedotoxin (also known as grayanotoxin). Rarely lethal to humans (and used medicinally in some herbal disciplines), this compound causes dose-dependant overstimulation of the central nervous system with symptoms including various cardiovascular effects (mainly low blood pressure and cardiac rhythm disorders); nausea and vomiting; and a change in consciousness. The effects commence shortly after ingestion and last around two days. These effects are also transferred to honey made from the nectar of the flowers. In some parts of the world bees are used to deliberately produce a honey rich in andromedotoxin which is then eaten for its supposed medicinal, hallucinogenic and aphrodisiac effects.
In contrast to humans, many other creatures are more susceptible to the toxin and it has sometimes proved lethal to grazing animals and household pets. Some forms of honeybees are also killed by the toxin (resistant forms of the bee are used for honey production). Bumblebees are not affected, however, and are also more efficient in pollinating rhododendron flowers, so one theory is that the toxin is produced by the plant in order to favour the bumblebee and improve fertilization rates[
1668- Title
- Grayanotoxin Poisoning: ‘Mad Honey Disease’ and Beyond
- Publication
- Cardiovasc Toxicol (2012) 12:208-215
- Author
- Jansen S.A. et al
- Website
- https://doi.org/10.1007/s12012-012-9162-2
- Publisher
-
- Year
- 2012
- ISBN
-
- Description
- An in-depth review of the literature on the toxic effects of a toxin widely found in the family Ericaceae
].
Botanical References
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
,
266- Title
- Flora of China
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/china/
- Publisher
- Missouri Botanical Garden Press; St. Louis.
- Year
- 1994
- ISBN
-
- Description
- An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
Range
E. Asia - China (Yunnan), northeastern Myanmar
Habitat
Coniferous and mixed forests, also in scrub; at elevations from 2,150 - 2,700 metres[
184- Title
- Shrubs.
- Publication
-
- Author
- Phillips. R. & Rix. M.
- Publisher
- Pan Books
- Year
- 1989
- ISBN
- 0-330-30258-2
- Description
- Excellent photographs and a terse description of 1,900 species and cultivars.
].
Properties
Other Uses Rating | |
Habit | Evergreen Shrub |
Height | 3.00 m |
Cultivation Status | Ornamental, Wild |
Cultivation Details
Rhododendron griersonianum can withstand temperatures down to about -10°c when fully dormant[
184- Title
- Shrubs.
- Publication
-
- Author
- Phillips. R. & Rix. M.
- Publisher
- Pan Books
- Year
- 1989
- ISBN
- 0-330-30258-2
- Description
- Excellent photographs and a terse description of 1,900 species and cultivars.
]. Although cold-tolerant when dormant, the flowers and young growth of Rhododendrons are very susceptible to damage by late frosts in regions where these are likely to occur after new growth has commenced in the spring[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Succeeds in a most humus-rich lime-free soils except those of a dry arid nature or those that are heavy or clayey[
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
]. Prefers a peaty or well-drained sandy loam in a sunny, sheltered position[
11- Title
- Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
- Publication
-
- Author
- Bean. W.
- Publisher
- Murray
- Year
- 1981
- ISBN
- -
- Description
- A classic with a wealth of information on the plants, but poor on pictures.
]. Succeeds in sun or shade, the warmer the climate the more shade a plant requires[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Tolerant of more sun and drought than most species in this genus[
184- Title
- Shrubs.
- Publication
-
- Author
- Phillips. R. & Rix. M.
- Publisher
- Pan Books
- Year
- 1989
- ISBN
- 0-330-30258-2
- Description
- Excellent photographs and a terse description of 1,900 species and cultivars.
]. A pH between 4.5 and 5.5 is ideal[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Plants are very tolerant of pruning, especially when grown in the milder areas of the country, and can be cut back severely if required[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Succeeds in a woodland though, because of its surface-rooting habit[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
], it does not compete well with surface-rooting trees[
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
]. Plants need to be kept well weeded, they dislike other plants growing over or into their root system, in particular they grow badly with ground cover plants, herbaceous plants and heathers[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Plants form a root ball and are very tolerant of being transplanted, even when quite large, so long as the root ball is kept intact[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
The seeds of this species take almost a year to ripen from flowering[
266- Title
- Flora of China
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/china/
- Publisher
- Missouri Botanical Garden Press; St. Louis.
- Year
- 1994
- ISBN
-
- Description
- An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
].
Plants in this genus are notably susceptible to honey fungus[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Edible Uses
None known
Medicinal
None known
Agroforestry Uses:
Plants can be grown as a hedge, responding well to trimming[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Other Uses
None known
Propagation
Seed - best sown in a greenhouse as soon as it is ripe in the autumn and given artificial light. Alternatively sow the seed in a lightly shaded part of the warm greenhouse in late winter or in a cold greenhouse in mid spring. Surface-sow the seed and do not allow the compost to become dry[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Pot up the seedlings when they are large enough to handle and grow on in a greenhouse for at least the first winter.
Layering in late July. Takes 15 - 24 months[
78- Title
- Propagation of Trees, Shrubs and Conifers.
- Publication
-
- Author
- Sheat. W. G.
- Publisher
- MacMillan and Co
- Year
- 1948
- ISBN
- -
- Description
- A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
].
Cuttings of half-ripe wood, August in a frame. Difficult[
78- Title
- Propagation of Trees, Shrubs and Conifers.
- Publication
-
- Author
- Sheat. W. G.
- Publisher
- MacMillan and Co
- Year
- 1948
- ISBN
- -
- Description
- A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
].
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