top of page
Chimacum Woods Logo lighter.png


Species Rhododendrons Descriptions By Name
R. insigne

R. insigne delights with candy-striped flowers of pink and white supported by beautifully polished dark green leaves.  The indumentum on the backside of the leaf is an equally polished silver.


R. insigne makes a compact shrub that may reach four feet in ten years.  It likes to branch and prefers a bright spot with some sun.  It comes from Yunnan and Sichuan in western China.  

R. insigne is unique among rhododendrons because it insists on being deadheaded after blooming in order to initiate its new growth!  (Usually deadheading just makes the plant look better).


This plant does NOT like fertilizer, especially when young. 

It wants light but not prolonged direct sun, so a mix of sun and shade is perfect. Well-aerated soil with good drainage is a must, and even moisture keeps it growing well. It is hardy to 0°F.

R. irroratum ssp. irroratum including Ningyuenense Group

R. irroratum’s flowers range in color from white to rose pink and come with or without spots. Flowers of the R. irroratum Ningyuenense Group are yellow and the leaves are a lighter green.  Either variety forms an upright vigorous shrub becoming (in 10 – 20 years) a small 10 foot tree. While common in Yunnan and southern Sichuan, botanists are still sorting out the exact nature of this species.

R. irroratum will like a fair amount of sun, but don’t cook it. Give it small amounts of fertilizer on Valentine’s Day and Mother’s Day and gentle but consistent watering. It's hardy to 5°F or so.


R. japonicum

R. japonicum is one of the Japanese deciduous azaleas.  We know it best as one of the parents of the Mollis group of deciduous azaleas, many of which are simply variants of this species.  It has a long history in Europe, where it was introduced in 1830.


The flowers appear in May and are a soft, clear orange towards the apricot. Red, pink and yellow-flowered forms also occur.  The leaves are a soft apple green darkening with age.  In the fall they turn lovely shades of yellow and red.

R. japonicum is easy to grow and is a reliable “good-doer.”  It will reach a height of three to four feet in ten years and can be quite showy in full bloom.  Flowers appear just as it’s breaking into new growth. This plant will like filtered sun but not dense shade; a bright, open location works best. It’s hardy for western Washington (to -5° F.) and it's also fairly heat tolerant.  In Japan it occurs from the lowlands on up into the mountains

R. keiskei

A wonderful present from Japan, R. keiskei is a variable small leaf member of subsection Triflora. The light yellow flowers appear in early spring – March here in the Pacific Northwest. It ranges in height from a small mound to more upright forms but rarely exceeds three feet. The plant featured here is grown from seed from two of the smallest dwarf forms and should not exceed one foot in height – ever!

Winter foliage usually adds an appealing reddish cast to the leaves. Too much sun will also turn the leaves red, so give R. keiskei a mix of sun and shade even though it has relatively small leaves

R. kesangiae

The forebears of this superb big-leaf plant live in the forests of Bhutan.  It was only recognized as a distinct species in 1989 even though it had been known for years!  R. kesangiae will gradually grow into an upright shrub or a small tree - perhaps seven feet in 10 years. It holds promise to become the best do-er of the big leaves, as it is more reliably hardy and less fussy about conditions! It does need protection from high winds as the petiole tends to break. Rose pink flowers on the mature plant gradually fade to pale pink in April or May.  As the leaf bud starts to elongate, the wax covering on the bud gets spread over the emerging leaves and then begins to flake off. Often mistaken for a disease, it's just Mother Nature being protective.  The plant is hardy to 5°F.

R. keysii

This rhododendron is truly unique. Its flowers are tubular and come out in clumps!  Consequently, there are masses of orange tipped in yellow hanging not just from the tips of branches but also from the sides of the branch.  If you are lucky, you might have the rare plant whose flowers are only yellow.  Who would guess this is a rhododendron!

R. keysii is a willowy relative of R. cinnabarinum.  It likes a bright location but wants protection from hot sun.  It responds to pruning and so can be kept in bounds, but it is best allowed to reach six or seven feet so that you can walk under its gracefully bending branches and have its flowers at eye level or dangling overhead. Beware of dive-bombing hummingbirds who love the flowers and who believe that they alone are entitled to enjoy it.

R. lanigerum

Here's a robust shrub with an exceptionally large truss made up of 20 - 35 flowers in shades of pink, reddish-purpler, cherry-red to scarlet with shades in-between. The flower buds are large and round.  Leaves are longish and sometimes have a slight creamy-white indumentum on the upper surface but mature to a shiny deep green. The undersides have a thin, whitish to fawn indumentum.

R. lanigerum is a larger shrub, growing to 5-6 feet in ten years and then continuing on to become a small tree. It needs some protection from scorching sun but otherwise enjoys a bright spot in the garden. It is hardy to 5 or so degrees Fahrenheit.

R. lepidostylum

Don’t have much room? Consider me, a dwarf topping out at three feet. Better yet, like blue? My foliage is among the bluest in the genus and stays that way. Tired of pink? My flowers are a soft yellow in keeping with my small size and come late in the season. I like to grow horizontally into a mounding shrub, maybe 2-3 feet in ten years.

I am a bristly, hairy fellow which, I think, adds interest. My leaves are covered with scales underneath as is my style, hence my name. I prefer an open location, but don’t burn me in unrelenting sun. I do like my roots in light, well- drained soil, and I appreciate small amounts of fertilizer on Valentine’s Day and Mother’s Day. Consistent gentle watering makes me happy. I’m hardy to -5°F.

R. leucaspis

A low-mounding gem from China, Tibet, and Arunachal Pradesh, R. leucaspis is wider than tall. Hairy leaves, bronze new growth and red/brown bark add interest. The dwarf habit makes this evergreen great for rock or alpine gardens.


R. leucaspis should grow to about 2 feet in 10 years in a sunny but not hot spot. In the wild, it is an epiphyte, growing on tree trunks and branches, so it will do well growing in a basket or on a tree stump.

In 1929 Lionel de Rothschild displayed these dwarf gems grown at Exbury and received the Award of Merit; they bloomed fully that early spring at the young age of 4 years from seed! Its name comes from the white shields of the ancient Greek hero Leucaspis.

It is hardy to approximately 5°F or -15°C.

R. lindleyi

R. lindleyi’s delicate yellowish-white bell-shaped flowers, usually plentiful, will delight you with their sweet scent.  Its forebears come from E. Nepal, S.E. Tibet or Manipur where they live among trees on the sides of cliffs. It’s named for Dr. J. Lindley (1799-1865), a botanist who served as secretary to the Royal Horticulture Society.

R. lindleyi has a “rangy” habit and does well planted at the foot of a wall or in a stump, where the long shoots can trail over an edge.  Alas, it is hardy to perhaps 15 – 20° F. It's not really suitable for containers (too rangy) and so needs a greenhouse or a warm climate for survival.

R. longesquamatum

Sichuan is the ancestral home of this shaggy and bristly-leafed plant which shows rusty-brown new growth in the spring.  Its name means “with long scales.” The striking mid-season foliage and hardiness make this a winner for the Pacific Northwest.


R. longesquamatum seems to be an easy plant to grow.  In ten years you may find it reaching about four feet.  It always has a distinctive look that stands out in the landscape.  Its hairs and its slight orange cast later in the season set it apart. It is hardy to -10° F.

R. lutescens

Here’s a sunny yellow that blooms in early spring accom-panied by willowy new growth in bronzy gold and red. It is easy to grow and wants a fair amount of sun. It grows quickly and blooms at an early age. It may reach six feet in ten years but is easily kept smaller as it responds well to pruning. Bark is a smooth brown and tends to flake.

R. lutescens is part of the Triflora subsection, a group of plants noted for their narrow pointed leaves. R. lutescens can provide lots of screening if that’s what you need. It prefers a sunny location that is bright, but it doesn’t like broiling hot afternoon sun. It's hardy to 5° F.

R. luteum

R. luteum is a deciduous azalea with a long history. Linnaeus first described it in 1753, and it was the foundation for the Ghent hybrid azaleas, famous for their vivid colors. R. luteum is intensely fragrant, filling the garden with a sweet,  intoxicating sense of spring. Autumn foliage colors range from red and orange to purple. A winner from Turkey in all seasons.

R. luteum does quite well in an open sunny location. It’s a tough plant that is both cold and heat resistant. It may reach 4 – 5 feet in ten years. Supposedly the Roman army ate honey from R. luteum, fell into a stupefying sleep and was slaughtered by the Persians.

bottom of page