W-X-Y-Z
Species Rhododendron Descriptions By Name
As seen in Tibet
Can be floriferous
As seen in Tibet
R. wardii
R. wardii is the classic yellow species. It’s been cultivated in the western world since 1913 and was used ever since by hybridizers to create that truly great yellow. It comes with or without the red blotch, but either way it’s a solid yellow. We saw both forms as they merged in SE Tibet. The bluish cast to its rounded leaves only adds to its need to be in your garden.
It is closely related to R. souliei and is found in NW Yunnan, SW Sichuan and SE Tibet, but it crosses over to Arunachal Pradesh, where it merges with R. campylo-carpum. And you think your family relationships are complicated?
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Frank Kingdon-Ward (1885-1958) was a renowned British plant hunter. R. wardii is named after him. It will make a nice mound of 4 -5 feet in ten years and most forms will flower at a young age. Give it some sun and perfect drainage. It’s hardy to 0°F, -18°C.
With foliage to die for
There's orange-brown indumentum hiding underneath
With foliage to die for
R. wasonii
R. wasonii is a glossy leafed beauty that will form a compact mound reaching perhaps four feet in ten years. Flowers can be yellow, white or pink. The brownish-red indumentum makes the underside of the leaf as interesting as the polished top side. Once again, the foliage wins the day, as is true for most of the Subsection Taliensia. This plant is truly in a class by itself as it has no close relatives.
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R. wasonii will like a fairly bright cool spot in your garden. Morning sun is excellent, protection from strong hot afternoon sun a must. Regular pinching of single leaf buds will help keep it compact.
Bright white
A yellow mid-rib
Bright white
R. watsonii
R. watsonii is a rarely seen “big leaf” rhodie that stays compact! It has a short flattened petiole (the part that attaches the leaf to the stem) that is yellow. The yellow then continues down the midrib of the leaf, giving a sort of striped effect. The underside of the leaf sports a plastered silvery-white indumentum that can take years to develop. Flowers are white, perhaps tinged pink, and are small in comparison to the leaf. Once again, species are about the plant, not just the flowers.
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We can expect the plant to reach four feet of so in ten years. R. watsonii is hardy to approximately 5° F. Hardiness depends on many factors, so use this number as a guide. Mostly, it’s distinct enough to deserve a place in your garden.
Soft pink bells
Bronze and gold new growth
Soft pink bells
R. williamsianum
This delightful plant provides a show when in bloom (April – May) with its pink to white bells usually with two to three flowers per truss. Later the new bronze growth provides a second show. It’s very compact and slow-growing, taking many years to reach two and a half to three feet high and two or three times that in diameter. Its forebears originated in Sichuan at heights of 8,000-10,000 feet.
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R. williamsianum loves (and needs) the sun, but you still can cook it if you insist on putting it in cactus territory. Also, being a refined member of the genus, it eschews gluttony, preferring to abstain from over-consumption of fertilizer - a little compost will be sufficient, thank you.
Two-toned flowers
The new growth is pretty impressive too!
Two-toned flowers
R. wiltonii
R. wiltonii is a class act. Its foliage is quite distinctive, with a deeply veined upper surface that is almost wrinkled and an underside that boasts cinnamon to rusty red indumentum. It likes to branch and will form a rounded shrub of four to five feet in ten years.
And yes, with age, it is quite free flowering, producing soft pink blooms that are spotted and blotched in darker shades of pink and rose. R. wiltonii is one of those “good do-ers.” It is easy to grow with lots of return for your gardening effort. It comes from western Sichuan and has some regional variation. It's hardy to -10° F.
Small yellow flowers
Small yellow flowers
R. xanthostephanum
This lovely plant can be found native to Burma, Tibet, China and Vietnam. It lives there in forests and pastures and on the sides of cliffs. Its bright yellow flowers and the silvery brown leaf underside distinguish it. Its lovely, red, peeling bark adds more interest.
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It’s a showy plant that can sprawl, but you can train it and keep it manageable. Since it hardy only to 15° Fahrenheit, it’s a good candidate for a large pot, so you can bring it into the garage or greenhouse in the winter.
Now imagine these clusters all over the plant!
Now imagine these clusters all over the plant!
R. xichangense
(xi=SHE). Here’s a new introduction from China that has great merit. It is basically a smaller version of a long time classic, R. davidsonianum, a beautiful pink that has graced our gardens since 1904 but gets large with age. R. xichangense should limit itself to a meter or two at the most.
It is a member of Subsection Triflora and has the characteristic willowy growth and fragrant leaves, as well as an ability to take the sun, making this an ideal plant for the smaller garden.
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R. yakushimanum - see R. degronium subsp. yakushimanum
Soft lavender with rounded leaves
It's 2" wide, 3" long and feels like it's made of leather!
Soft lavender with rounded leaves
R. yuefengense
This rhododendron may be the best introduction in a decade (or even a century) because of its astoundingly thick, leathery foliage with its roundish leaves. Better yet, it blooms at an amazingly early age. While it seems to grow in every which direction, all is forgiven in lieu of its hardiness, vigor and stunning beauty.
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R. yuefengense may reach five feet in ten years, but we really don’t have any long term data on height. Guesses think it will be wider than tall. It likes moderate sun. It seems to be hardy to 5° F.
An unusual blue from Sichuan
A more typical white
An unusual blue from Sichuan
R. yunnanense
This species is one of the great sights of the Yunnan province in Western China where one can see whole hillsides covered in pinkish, white flowers. The blooms, up close, have delicate blotches olive, deep green, deep rose to brownish crimson. No two plants have the exact same blotch (unless the plants are grown from a cutting).
R. yunnanense can grow tall and willowy, and since it can take the sun, it can grow into a lovely screen if you plant several in a row. It’s free flowering even from a young age. R. yunnanense will appreciate some pruning to keep a nice shape. It will also bloom in shady areas and can tolerate a somewhat drier site as well. It's hardy to 0° Fahrenheit.
Soft pink to white
Soft pink to white
R. zaleucum
This is a member of the Triflora subsection of rhododendrons, all of whom are known for their graceful, willowy habits. R. zaleucum is distinguished by the glaucous or nearly white underside of the leaf. Zaleucum means “very white.” The flowers easily borne are white or flushed with pastels.
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R. zaleucum leaves are aromatic, especially when crushed. The early growth is often reddish or bronzy. This plant will take a lot of sun, bloom easily, and make a distinctive addition to your rhody garden. It is hardy to 0° Fahrenheit.