The cutting is best done at flowering time and the plant should be 
watered heavily and given a little stimulant in the form of 
sulphate of ammonia, 2 ozs. per sq. yd. and thoroughly watered 
into the soil. 
After flowering, the re- 
moval of old flower clus- 
ters will help conserve the 
plant’s strength and prevent 
the setting of seed pods. In 
some hybrids, the number of 
flower buds which form each 
year is often too many for the 
plant’s good and a good meas- 
ure of what to leave when dis- 
budding is one bud to each 
square foot of leaf surface. By 
so doing, an even show of 
flowers is ensured throughout 
the years and the plant is not 
weakened by the prodigality 
of its blossoms. 
PINCH OFF OLD FLOWER 
PESTS AND DISEASES 
Insect pests attacking Rhododendrons may be divided into two 
general classes: 1. Sucking insects, which pierce the leaf surface 
and suck out the sap, causing discoloration and ultimate defolia- 
tion. 2. Chewing insects, which bite out portions of the leaf 
leaving holes and scalloped margins. 
Of the first group, thrip, aphids, and lacewing fly are the 
most common. The presence of thrip is readily ascertained by 
the silvery appearance of the leaf surface. The adult insect may 
be recognized by its flat body, barely 1/20 inch long and narrow 
in proportion to its length. They are colorless in the early stages 
and become almost black with age. A forceful spray consisting 
of two teaspoonfuls of 50% wettable DDT to one gallon water 
applied to the leaf undersurface will effectively control this pest. 
The lacewing fly is about 1/8 inch long and 1/16 inch wide 
and has transparent lace like wings which are held flat against 
its body. The eggs hatch out in early May and control may be 
obtained by spraying with a 1% solution of Volek Summer Oil 
to which has been added Black Leaf “40” at the rate of two 
teaspoonfuls per gallon of the solution. It is important that the 
spray is directed towards the underside of the foliage and that 
it is applied during late May or early June. Aphids cause a dis- 
tortion of the young soft growth, the effect of which is apparent 
as the leaves mature. Control is by spraying at ten day intervals 
with Black Leaf “40”, two teaspoonfuls to one gallon of water. 
The addition of a soap spreader will assist materially in de- 
stroying this pest. 
In group two, the strawberry root weevil and caterpillars are 
particularly destructive. The larvae of the strawberry root 
weevils are usually active in fall and winter, working on roots 
and stems near the ground. They may girdle the stem, destroy- 
ing the tissues so deeply as to prevent the conduction of food 
material to the roots. The adult form of this insect feeds on 
the leaves, chewing out small scalloped areas along the leaf 
margins. Control of the adult is effected by broadcasting one 
of the proprietory applebaits around the crown of the plants, 
If they are applied according 
to directions and kept up at 
intervals of from ten days to 
two weeks for eight or nine 
applications, reasonable suc- 
cess will be assured. For con- 
trol of the larvae stage, the 
following is recommended. 
Apply arsenate of lead dust 
(3 ozs. per sq. yd.) and work 
into the top four inches of soil 
before planting or dust around 
the crown of the plant and 
lightly work in with the fin- 
gers, Caterpillars occasionally TYPICAL 
chew out portions of the leaf | NJURY CAUSED 
and may be controlled by BY ADULT STRAWBERRY W EVIL 
spraying the foliage with ar- 
senate of lead. 
The best preventive against 
destructive organisms which 
ADULT 
STRAWBERRY 
WEEVIL 
PEST AND DISEASES (Continued) 
attack plants is to keep the plants in good health and to protect 
them against cold biting winds, excessively hot sunshine, or 
any factors which may contribute to any injury which allows 
an organism to gain admittance to the plant tissues. Fungus 
diseases on Rhododendrons are relatively rare. There are two 
to be especially guarded against; namely, ‘leaf spot” and “bud 
blast”. “Leaf Spot’, as its name implies, is detected by the dark 
brown spots on the foliage. The spots vary in size and may be 
circular or angular in outline. Sometimes they have a silvery 
area in the center. Control is by picking off the diseased leaves 
and burning, then spraying the entire plant with Bordeaux 
Mixture at 10 to 12 days inter- 
vals during the growing sea- 
son, “Bud blast” appears in the 
early spring and often follows GIRDLED STEM BELOW 
excessively heavy rains in the SURFACE CAUSED BY 
fall. In early spring outer bud LARVAE OF STRAW- 
scales take on a silvery appear- 
ance and begin to drop. The 
infected buds turn brown and 
dry up and, if not removed, 
will remain on the plant for 
one or two years. To control, 
pick and burn all infected buds 
and spray the plant with Bor- 
deaux Mixture at intervals of two weeks. 
_ BERRY WEEVIL 
LARVAE OF 
o\ STRAWBERRY WEEVIL 
CULTURAL DIFFICULTIES 
Most of the difficulties encountered by gardeners in pursuit 
of their hobby may be attributed to improper cultural practices 
Perhaps the most common error on the part of the grower is 
planting Rhododendrons too deep, which is followed by short 
annual growths, increasingly smaller trusses and leaves, and 
finally the demise of the plant. 
Yellowing of the foliage may be caused by several conditions. 
If the leaf turns yellow while the veins remain green, it would 
indicate that the soil was too alkaline. Such a condition may be 
temporarily corrected by applying acid fertilizers or by the 
application of aluminum sulphate at the rate of five pounds per 
100 square feet and watered in. It is doubtful that either of these 
two remendies would be of much permanence, and the only 
worth-while solution is to dig the plant and replant in a humusy 
material such as was recommended in the paragraph on soils. 
Overall yellowing of the foliage may be caused by an im- 
properly drained soil and a consequent reduction of oxygen at 
the root zone. The degree of yellowing differs from that caused 
by an alkaline soil in that the leaf is yellow all over, including 
the veins. The remedy is obvious, namely, to provide better 
drainage either by tiling or by removing the plant to a more 
suitable location. Too much light will also cause a yellowing 
of the foliage, particularly on the larger leaved hybrids as the 
Loderis, Dr. Stocker, etc. 
The failure of plants to form flower buds is sometimes en- 
countered. In the case of Loderi, Gill’s Crimson, Faggetter’s 
Favorite, Beauty of Littleworth, etc., buds are not produced 
until the plants are several years old. This is a normal situation 
and due to heritable characters. Too much overhead shade may 
cause a lack of flowering wood to be formed and in its place 
promote a leggy thin growth. Some hybrids may give an abun- 
dance of flowers one year and the next year form only growth 
buds. This condition can be overcome by partially disbudding in 
the early spring, allowing one flower bud to remain per square 
foot of leaf area, This will ensure an even show of flowers from 
one year to the next. 
If the cultural methods suggested under the various para- 
graphs are carefully followed, there should be little difficulty 
in growing Rhododendrons successfully. Once properly estab- 
lished in a suitable soil they demand little attention outside of 
an abundance of water during the growing period. 
TEN PER CENT OFF ON SIX OR MORE PLANTS ORDERED FROM THIS CATALOG 5 
