Do you know there are some only a few inches high that rival the giants in beauty?
The rhododendrons most of us know are so immense and magnificent that the first glimpse of a dwarf one is different from anything we might have imagined.
Even to those familiar with a number of the smaller kinds, a delightful surprise is in store at first sight of the smallest and rarest.
Dwarf Rhododendron
The familiar Carolina rhododendron is often called a dwarf because of its somewhat diminutive leaves and flowers.
However, when you meet it in our southern mountains, where it arches high overhead, you’ll agree we must look elsewhere for true dwarfs.
Lapland Rhododendron
If you visit the summit of Mount Washington in New Hampshire or the mountains of British Columbia in late May or early June, you will find spreading mats of tiny leaves a few inches high, all but buried in azalea-like purple flowers.
This is the Lapland rhododendron, Rhododendron lapponicum, a veritable dwarf inhabiting much of the Arctic and creeping southward only on high peaks and ridges.
Though hugging the ground, it can spread to a diameter of several feet, with sturdy branches straggling from a central trunk.
The Lapland rhododendron will hardly do for gardens as it dislikes the heat of a lowland summer, but some of its 60-odd slightly taller relatives from the uplands of Asia can be grown and are highly praised in England.
Some species can be made to thrive in some eastern American climates if the soil is kept moist and prepared with generous admixtures of acid peat and gravel.
They are:
- Rhododendron Fastigiatum
- Rhododendron Impeditum
- Rhododendron Intricatum
Given moderate sunshine, they will bloom gloriously in various shades of deep blue-purple to lavender.
Yellow Compatriots
Their yellow compatriots, Rhododendron flavidum (primulinum) and Rhododendron chryseum seem more exacting.
It usually requires the sunny bank of a pond or stream so that their roots can reach abundant water yet have no soil that is well drained immediately around them.
Even when given every care, these rhododendrons of the Lapland alliance suffer from certain drawbacks.
During our colder winters, they turn brown, drooping their 1/2-inch leaves against the stalks until you would surely take them for dead. Evergreens should not behave in such a manner.
Mayflower Rhododendron
We find something better in the Mayflower rhododendron from western China, R. racemosum.
In all weather, it boldly holds its bright green fingernail-size leaves, which are silvered beneath, on sturdy branches that spread into a dense, foot-high bush.
Even after many years, the bush may be no more than a foot in diameter. The best forms keep to this small size and remain dependably hardy north of New York City.
Small but numerous flowers, varying from pure pale pink to deep rose, offer a gorgeous display in May.
This little rhododendron has many races originating in different parts of Szechuan and Yunnan’s provinces; some grow considerably larger, and some are not hardy.
To ensure success, plants should be obtained nearby, not from a nursery in a warmer climate.
About twice the size of the Mayflower rhododendron is the hybrid Conestoga, obtained from a cross with the Carolina rhododendron.
It produces clusters of charming pale flowers all over the tips of its many branches.
Attractive Conestoga Plant
Conestoga is certainly a most attractive plant for southern Pennsylvania and Long Island, but it fails to winter northward.
Windbeam, the hardy and vigorous seedling of Conestoga, seldom grows more than 2’ feet high after a dozen years.
It possesses the typical beauty of its parent, blossoming copiously every year yet entirely indifferent to winter cold. Equally hardy and more compact is the white Wyanokie.
Yellow Rhododendron Varieties
Rhododendron Keiskei
Japan has given us a fairly dwarf yellow, Rhododendron keiskei, moderately hardy if well sheltered, shaded, and deeply mulched.
A good place for it is in front of larger rhododendrons. However, it must be moved forward every three or four years, or the rapid growth of the larger plants will smother it.
Unlike Rhododendron racemosum, which will flower well in its third year, Rhododendron keiskei needs at least 5 or 6 years before offering much of its delightful soft, ocher-yellow bloom.
Plants should be selected when in flower since the greenish-yellow forms, though good, fall short of the finest yellows.
Rhododendron Hanceanum
Rhododendron hanceanum, the most superb of all dwarf yellow rhododendrons, originated in England.
As yet has not been properly tested for hardiness in the eastern part of the United States.
It probably is not a form of the rather inferior Rhododendron hanceanum. But a chance hybrid between that species and a smaller yellow, perhaps Rhododendron chryseum.
If so, there is a good chance that this wonderful plant may endure our climate.
In North Wales, it is almost completely buried under clouds of soft, pale yellow bloom, although it is less than a foot in height.
Guyencourt Rhododendrons
Hybrids between R. keiskei and R. pubescens, known as the Guyencourt rhododendrons, may be seen in some of the most celebrated American rock gardens.
Their narrow gray-green leaves, which are covered with soft hairs, are carried on red-brown twigs.
As the buds, too, are vivid brown, the foliage pattern displays a pleasing and highly unusual texture, while the flowers vary from pale yellow to pink and white.
These plants may reach 3′ feet tall, but not until many years have passed. Named forms in different colors will soon be listed.
Rhododendron ‘Ramapo’
Ramapo, a hybrid between the Carolina rhododendron and the Chinese Rhododendron fastigiatum, possesses the best virtues of the Lapland rhododendrons with few of their faults.
Its leaves remain green or with a purple tinge even in the coldest weather and do not curl or droop appreciably.
The plentiful flowers are bright violet, and the new growth, which breaks before the flowers fade, is a pleasing glaucous green.
Smallest Rhododendron
Perhaps the smallest of all rhododendrons is Rhododendron radicans, from the Chinese mountains.
It has pointed leaves a fraction of an inch long on completely prostrate, mat-forming stems.
From this godlike plant, almost pansy-like purple flowers an inch across are thrust up a couple of inches, one to a stalk.
It would be lost if planted elsewhere than in a rock garden, where it is reasonably hardy in a peat-gravel mixture, although rather difficult to please.
Rhododendron Repens
Most striking is the vinelike Rhododendron repens, never rising more than a few inches.
In spring, it is spangled with fiery crimson bells an inch long, nestling among leaves about half that size.
The plant appears to be nearly hardy but is subject to fungus diseases which usually carry it off before it has a chance to flower.
It is in no hurry to flower here, but in its native Burma, it fairly paints the mountains.
There is little chance of success with it anywhere but on the Pacific Coast, yet it is well worth trying because of its color. R. foresti is almost identical.
Related Species
Several related species are:
- Rhododendron sanguineum
- Rhododendron aperantum
- Rhododendron Citriniflorum
- Rhododendron horaeum
Others grow only a little higher, blooming in the purest shades of red and yellow.
But all are afflicted with the same ailment as Rhododendron repens. The leaves blacken and fall off until nothing except a few bare sticks are left.
Rhododendron Leucaspis
Eventually, hybrids between these choice treasures may bring us a measure of their charm.
Easily grown where it is hardy, Rhododendron leucaspis presents a contrasting picture, making a pleasing little shrublet with densely hairy leaves and cream-colored, wavy flowers 2” inches across.
It is not dependable anywhere but along the Pacific Coast, although it comes from Tibet.
It can, however, be wintered easily in a shaded cold frame, and the pot set in the open when about to bloom but returned to shelter on frosty nights. So it is worth the trouble.
Rhododendron Keleticum
A pretty dwarf with lilac-like and lilac-colored flowers has found its way into eastern rock gardens under the wholly erroneous name Rhododendron keleticum.
That species belongs in the Saluenense series with Rhododendron radicans, while the plant masquerading under its name is a close relative of Rhododendron anthopogon.
In a different series, it is probably a new introduction from Tibet. It is hardy and well worth growing.
Rhododendron Williamsianum
No account of dwarf rhododendrons is complete without mentioning Rhododendron williamsianum, found only on a single mountain in western China.
Eventually, it does reach a height of 3′ or 4′ feet but is a dense, well-rounded plant from which exquisite nodding pink bells rise just clear of the little heart-shaped leaves.
It is a top favorite among all who know it. It will linger along for years in sheltered spots around New York City and grow a little. Some day we hope to see it flower.
Requirements Of Dwarf Rhododendrons
The requirements of dwarf rhododendrons are nearly identical to those of their larger relative.
An acid soil high in humus is lightened with some coarse sand and enriched with leaf mold or sedge peat.
This soil must be kept moist but well drained. The ground must be mulched and never tilled or disturbed.
Instead of a leaf mulch, many do well when mulched with gravel or small stones; pine needles also make an excellent mulch.
A north slope lightly shaded by oaks and shielded from strong wind is ideal for many.
More Sun for Lapland Rhododendrons
Lapland rhododendrons need more sun to keep low and bushy; Rhododendron racemosum will also take nearly full sun.
The roots of all the dwarfs except Rhododendron keiskei crave contact with stones since they come from the cliff, scree, and stony mountain meadow. So the rock garden is well suited for them.
The day may not be far distant when many new names can be added to our list of hardy small rhododendrons.
New forms, no doubt, will be readily growable in the average garden and give no more trouble than today’s azaleas.
44659 by G. G. Nearing