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Species Rhododendrons Descriptions By Name
R. calendulaceum

R. calendulaceum is a deciduous azalea from the East Coast of the United States worthy of growing on the West Coast. Its flowers range from red to orange to yellow but are always vibrant. Our plants are grown from seed collected by some of the best East Coast connoisseurs of the native azaleas of the Eastern US. It made its way back to Europe by 1750 because the early immigrants to the Colonies thought it might be of value to the nursery trade.

R. calendulaceum may reach five to six feet in ten years. It enjoys the sun and gives good fall color. Enjoy it growing along the Blue Ridge parkway or in your own garden. Unlike many East Coast azaleas, it does not seem to hybridize readily with its kinfolk.

Fertilize on Valentine’s Day and Mother’s Day. Provide well-aerated soil and gentle watering.
 

calendulaceum
R. calophytum

R. calophytum  is one of the old classic species rhododendrons that still adds elegance to a woodland garden. The long leaves are remarkable and the white-to-pink flowers with long pistils and yellow stigma emerge fairly early in the season in large trusses. With age, it will become a a vase-shaped upright shrub with room for other shade lovers under its spreading canopy.

R. calophytum wants a fair amount of sun  for best blooming, but filtered shade protection from full sun on hot summer afternoons. Give it small amounts of fertilizer

on Valentine’s Day and Mother’s Day along with gentle watering. It should reach five or six feet in ten years.

calophytum
calostrotum ssp. calostrotum
R. camelliflorum

R. camelliiflorum is a unique rhody with no close relatives.  It is native to eastern Nepal and Bhutan, where it usually grows epiphytically on trees or rocks.  It develops a peeling reddish bark.  The leaves and young stems are heavily covered with scales. Flowers are usually white but there are wine red flowered plants in the wild. 

R. camelliiflorum might reach four feet tall in ten years, but it will always have a free spirited form that is in marked contrast to its more formal distant cousins.

 

A mix of sun and shade is best but.  perfect drainage is essential. Small amounts of fertilizer on Valentine’s Day and Mother’s Day will keep it happy.

 

Since R. camelliiflorum is epiphytic, it should be a good candidate for a hanging basket or try propping it in the notch of a tree branch, strategically anchored if necessary.  It’s the kind of plant that invites experimentation. It's hardy to 5°F.

camelliflorum
R. calostrotum ssp. calostrotum

R. calostrotum comes in several forms. The ssp. calostrotum form features bluish leaves on a small, compact plant that may reach three feet. Flower color is quite variable, ranging from the blues to pinks to rose-crimson. It is native to northern Myanmar and western Yunnan, often growing in alpine meadows.

Give it a sunny location with good drainage. It responds to pinching to keep it bushy. Fertilize on the February, May schedule, and don't forget to water it. 

R. campanulatum

Grow this plant for its foliage – substantial elliptic gems of deep green.  The underside of the leaf is covered with a tawny indumentum that appears to be plastered in place.  The flowers will vary – pale lilac to white. This species comes from the southern Himalayas – Kashmir to Sikkim – and therefore has lots of variation.

R. campanulatum will make roughly a five foot bush in ten years.  By then it will have a lovely trunk with grey to fawn bark.

 

R. campanulatum  will appreciate a bright location with protection from strong sun, small amounts of fertilizer on Valentine’s Day and Mother’s Day and gentle watering that keeps it moist. Good drainage with well aerated soil is a must. 

R. campanulatum evokes the feel of the lush vegetation characteristic of the Himalayas and adds an exotic touch to your garden.

campanulatum
R. campanulatum ssp. aeruginosum

This is the plant that every lover of blue foliage wants. It's just like the plain R. campanulatum except  (except? - that's the point) it's foliage is blue! It's not the easiest plant to grow, but we can excuse its fussiness in exchange for this astounding foliage.  On top of that, it's slow growing and may reach two to three feet in ten years.

Everything else is as described in plain old R. campan-ulatum. But who wants plain old.

campanulatum aeruginosum
R. canadense

Here is a deciduous azalea from the Eastern U.S. and Canada.  It has strap-like flower petals either deep rosy purple or white against bluish, green leaves which turn color (to purple or yellow) in the fall. Ultimate height – 3 ½ feet!

Plant in well-aerated, moist acidic soil; fertilize sparingly at Valentine’s Day and Mother’s Day. Give it more sun than shade

 

 R. canadense is stoloniferous – it sends out shoots from underground runners but it always remains dainty, not invasive. HARDY!! (It’s from Canada and Maine not to mention New Jersey!)

 

canadense
R. cerasinum

R. cerasinum  comes with two distinct flower forms. “Coals of Fire” is the nickname for the form with dark black-red bell-shaped blooms.  If you place the plant so that the morning or afternoon sun shines through the blooms, they will seem to glow.

"Cherry Brandy" is the nickname for the form with white flowers and a red picotee edging. 

In ten years, R. cerasinum can grow to three to four feet. It is hardy to 0°F.  It has medium-sized leaves and its lax truss will hold three to seven or more flowers.

cerasinum
R. changii

R. changii is a cute, small delight with polished leaves.  Part of the Maddenii family and named after a plant collector, Mr. Chang, it blooms in April or May.  We consider it hardy here, as ours overwintered outside at a young age.  You will enjoy a lovely purple tinge on the edge of new leaves.  Pinching the new growth on single stems should promote branching. 

This fairly-compact, dwarf shrub, may reach about two feet tall and three feet wide in 10 years.  It grows in thickets at 1600–2000 meters in Chongqing (SW China).

 

R. changii will like: filtered sun with small amounts of fertilizer on Valentine’s Day and Mother’s Day. Gentle watering and well-drained and aerated soil will keep it happy.

changii
R. chasmanthum — see R. augustinii ssp. chasmanthum
R. cinnabarinum

It’s hard to know whether the bluish foliage or the tubular flowers are the best part of this plant.  R. cinnabarinum comes in a wide range of colors and has a wide distribution in eastern Nepal, Bhutan, Sikkim, southeastern Tibet, Arunachal Pradesh and southwest China.

 

This plant may reach 6 feet in ten years.  It’s more upright than wide and does best with a fair amount of sun in an open location. R. cinnabarinum has aromatic foliage that is distasteful to weevils and so escapes being notched during the midnight munching these pests love to do. 

 

R. cinnabarinum  will appreciate small amounts of fertilizer on Valentine’s Day and Mother’s Day and gentle watering that keeps it moist. Good drainage with well-aerated soil is a must.

 

cinnabarinum
R. cinnabarinum Roylei Group

R. cinnabarinum from the Roylei Group has the deep red bells that distinguish it from its sisters. Otherwise its just another R. cinnabarinum, but one form does get to be called Magnificum.

cinnabarinum roylei
R. cinnabarinum ssp. xanthocodon Concatenans Group

A big mouthful of a name for such an outstanding plant in a series that contains lots of WOW. Our plants of  “concatenans” are grown from cuttings of a selected form of this species. The plant grows into a nicely rounded mound that may reach four feet or so in ten years.

 

“Concatenans” will appreciate a mix of sun and shade with protection from the hot afternoon sun. A bright spot is best. It also needs consistent moisture with good drainage as well as small amounts of fertilizer on Valentine’s Day and Mothers’ Day.

cinnabarinum xanthocodon
R. coeloneuron

R. coeloneuron is a newer introduction from western China.  It looks like a winner both because of its flowers – a perky pink – and because of its wonderful foliage.  The leaves have deeply impressed veins on the top and a soft brown indumentum underneath.  The plant branches easily and seems to make a well clothed upright shrub.  Its ultimate height is unknown, but we are expecting taller rather than lower and taller rather than wider.

R. coeloneuron seems to enjoy a fair amount of sun, blooming readily from a fairly young age.  It is not fussy and establishes itself under a variety of conditions. It seems to get confused with R. denudatum, which closely resembles R. coeloneuron.

coeloneuron
R. concatenans – see R. cinnabarinum ssp. xanthocodon concatenans group
R. concinnum

The willowy growth and fragrant leaves, as well as its ability to take the sun, make this an ideal plant for an appealing screen.  It’s hardy and makes a neat, compact bush. It responds well to pruning and is hardy to -5°F. It is a member of the Triflora subsection.

concinnum
R. crinigerum

This rhody has attitude.  The stiff bullate (puckered or blistered) leaves of dark green are covered with a mustard yellow indumentum underneath.  The new growth is very sticky.  The stems are bristly.

All that bravado masks soft pastel flowers that exude sweetness and light in early spring on a compact plant that spreads wider than high.

R. crinigerum may reach four feet in ten years and is hardy to approximately 5°F. It likes some sun just not relentlessly. It comes from Arunachal Pradesh, Yunnan and SE Tibet.

crinigerum
cumberlandense
R. cumberlandense

R. cumberlandense is another of those wonderful East Coast native azaleas that does well on the West Coast as well. Native to Virginia, Kentucky, Tennessee and points south, this is a low growing plant from higher elevations. The blooms come late – second half of June into July and are a vivid orange red mix. They appear after the new leaves have formed.

R. cumberlandense  may reach three feet in ten years. It is stoloniferous but not invasive. Fall brings bright red foliage for more enjoyment. We recommend more sun than shade but not the hot late day variety that would burn the foliage. Small amounts of fertilizer on Valentine’s Day & Mother’s Day are good as is gentle and consistent watering with well-drained, well-aerated soil. It seems to be quite hardy and isn’t particularly fussy.

R. cyanocarpum

Not only is it unnecessary to dead head this rhody – you won’t want to because the seed capsules (the part left over after the bloom is finished) are quite blue. The oval leaves also have a bluish cast with a yellow midrib. This is a tidy, formal sort of fellow with stiff branches that become part of an upright shrub. It may reach four to five feet in ten years.

R. cyanocarpum is not widely distributed in China. It most likely lives only on the Cangshan in Yunnan.

 

It prefers an open location that is bright but it doesn’t like the hot afternoon sun. Plant in light, well- drained soil, and give it small amounts of fertilizer on Valentine’s Day and Mother’s Day. It is hardy to 0°F.

cyanocarpum
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