Rhododendron 
Culture 
By ROY C. ROBINETTE 
The culture of Rhododendrons and other plants of the Rhododen¬ 
dron family, like Azaleas and Kalmias, as set forth here is revolutionary 
but simple. 
Rhododendrons have thousands of hairy, fibrous, surface-feeding 
roots located above or on top of the surface of the soil. These fibrous 
roots collect organic matter and form a sort of mat, or mold, that is 
naturally slightly acid, and which tends to soften and keep the soil in 
a bitter or sour condition. This mat acts as a sieve for the water which 
drains through it, holding the light and sour matter, while the heavy 
substances like earth or muck, are washed through, leaving it clean. It 
is from this mat that a substance or fertilizer peculiar to the needs of 
this plant is extracted. If the mat becomes clogged with earth or muck, 
which will happen if it is not located high enough to Have free drainage, 
the fibrous roots and mat itself will rot; and if it becomes alkaline 
because of the'use of limestone water, or water allowed to drain into 
it from limestone soil, the fibrous roots and mat will be destroyed. 
Immediately below the mat of roots are the feeder roots which con¬ 
tact or penetrate the soil, the depth depending on its friability. It 
would seem that their sole function is to furnish moisture, as the plants 
will thrive, even on freshly excavated earth or on a solid rock. Any 
kind of soil is suitable for Rhododendron culture, even, contrary to the 
general belief, limestone soil. The only difference in soils is their capa¬ 
city for retaining moisture. In limestone soil they should be so elevated 
as to avoid drainage into the top fibrous roots. 
When planted on a slope or terrace facing north, east or west; or south, 
when fairly well shaded, no further attention need ever be given them, 
providing the ball of the plant extends at least an inch above the surface 
of the soil, and is covered with a light mulch. 
In planting on level ground, it is entirely satisfactory to plant on 
top of theground, or even to elevate the plants as much as desirable, 
but in no case plant so that less than 2 inches of the ball will be above 
the surface of the soil. They should have some shade, preferably to the 
south. A 1-inch mulch yearly will furnish all the fertilizer needed. 
Rhododendrons usually have flat-bottomed root-systems, and it is 
necessary to plant them in such a manner that air-pockets will not 
form under them after the soil settles. This can best be done by working 
the soil into mud in the bottom of the hole to a depth of 1 inch, then 
soak the ball of the plant in water, put in place, cut the burlap away. 
straighten out top roots, press ball dowrn as tight as possible by stepping 
on it, fill hole, tamp around outer edges, then mulch. 
Use no garden fertilizers; their effect is invariably to destroy what 
you want to preserve. In the mulch, use no mixture of soil or earth; 
keep earth away from the top of the ball. 
Suitable material for a mulch is as follows: Any forest organic 
matter, as leaf-mold, leaves, twigs, rotted wood, roots, sawdust, moss; 
commercial peat or peat moss is good; also fruits and vegetables that 
are acid; litter, garden fiber, weeds, and grass may be used sparingly, 
but will heat if much is used and are not very desirable. 
Sunshine and alkali deteriorates an organic soil, while acid softens 
and preserves it. It is sometimes well to use an acidifying element, 
especially where it is necessary to water the plants with limestone water 
and a suitable mulch cannot be had. For this purpose, use a solution 
of 1 pound of aluminum sulphate dissolved in 20 gallons of water. This 
makes hydro-oxide of three acid elements, or the aluminum sulphate 
may be sprinkled on top of the ball at the rate of about one-fourth 
pound per plant, and then watered. If its use is to be continued, reduce 
the solution one-half. 
Rhododendrons will generally grow wherever a coniferous tree will 
grow. In some sections, such as low, elevated portions of the South 
and dry locations in the West, the transpiration or outward breathing 
of the plant must be considered. Select a cool, shady location protected 
from dry v inds. When plants with heavy foliage are being transplanted 
from their native grounds to these locations, they should be partially 
defoliated, allowing nature to restore according to the ability of the 
roots to furnish moisture. 
For doero-mg sick plants, elevate or dig a trench around them, use 
a fairly stiff hose to clean the earth from the top, then mulch. If new 
leaves die in spots and on edges it is a sure sign of a mucky condition. 
The American hemlock is excellent for planting with Rhododen¬ 
drons. When used among them, or as a background, it gives a natural¬ 
istic effect, as well as protection. 
The color and usual time of bloom of the different plants is as 
follows: Azalea nudiflora (pink), April 15 to May 15; Azalea calendulacea 
(flame-color), May 1 to June 10; Rhododendron cataivlnense (purple, 
red, lavender), May 15 to June 15; Rhododendron maximum (white, 
pink), June 20 to August 10; Kalmia latijolia (pink, white), June 1 to 
July 10; Rhododendron Sport, with foliage similar to Maximum, time 
and color of bloom similar to Catawbiense, only the color is deeper. 
Tourists desirous of seeing these plants in bloom will be furnished 
directions and routes upon request. A color display of unparalleled 
richness and beauty is spread over the hills every summer and is worth 
journeying far to see. 
NEW RIVER 
RHODODENDRON NURSERY 
1301 Princeton Ave., Princeton, W. Va. 
