DAHLIADEL NURSERIES 
“DAHLIAS 
during the heat of the day. These sucking insects 
do much to keep a plant from getting a good start. 
APHIDS (plant lice) are soft-bodied, sucking in- 
sects which usually work on the under side of the 
leaves in groups, causing the leaves to curl. Thrips, 
leaf-hoppers and aphids are possible common carries 
of virus diseases and should be kept in control for 
this reason, if for no other. 
CONTROL. We recommend the following spray. 
For thrips and leaf-hoppers use 2/3 0z. (4 teaspoon- 
fuls) of Pyrethrum Soap to 1 gallon of water, with 
the addition of Black Leaf 40 at the rate of 1 to 2 
teaspoonfuls to the gallon of spray, according to the 
ability of different foliage to resist burn. This kills 
not only by asphyxiation, but also by the toxic ac 
tion of the pyrethrum. 
For plant lice use.2 teaspoonfuls Pyrethrum Soap 
to 1 gallon of water. Black Leaf 40 is not necessary. 
Should a bush be infested with ants, spray bush 
and pour a few quarts of the Pyrethrum Soap spray 
Japanese beetle strength down the ant hill, or 
enough to fill the hill. This will do the dahlia no 
harm, but will kill the ants. 
Do not mix more than you are going to use the 
same day. This spraying can be done at any time 
of day regardless of weather conditions, except rain. 
Another control of thrips, leaf-hoppers and aphids 
is dusting with a good 3% nicotine dust. Apply in 
sunshine with temperature above 70 degrees at 
weekly intervals as a preventative from the time the 
plants are set or roots start to grow, and if any 
should appear then about every four days until they 
are controlled. For small plants a paper funnel on 
the end of the duster spout, held over the plant for 
about one minute when dusting, will increase the 
kill materially. 
During windy weather when dust cannot be ap- 
plied to advantage, overhead sprinkler used during 
the heat of the day will control red spider and check 
the leaf-hoppers and thrips. See “Irrigation.” 
By dusting or spraying before the presence of in- 
sects, it is doubtful if you will see any. As it is diffi- 
cult to procure nicotine dust and pyrethrum soap in 
most localities, we are listing them under ‘Dahlia 
Growers’ Supplies.” Page 48. 
INSECT CONTROL WITH A HOZE GUN is 
as simple as watering your garden. We have found 
this cartridge spray method very effective in the 
greenhouse as well for the control of Thrips, which 
is one of our most stubborn pests. A complete line 
of Insecticides and Fungicides is available, so prac 
tically all pests and fungus diseases can be con- 
trolled. It is the easiest way to spray of any method 
we have tried where a hose pressure of 35 lbs. or 
more is available. Full directions are supplied with 
each outfit. Descriptive pamphlet on request. See 
Hoze Gun listed on page 48. 
RED SPIDER in late years has caused consider- 
able damage to dahlias. This insect is barely dis- 
cernible with the naked eye and works with such 
rapidity that you may have a row of dahlias today 
and within a few days or a week all the lower leaves 
25 
will be as brown as cured tobacco leaves. There will 
be a very fine white web in evidence on the under 
side of the leaf. These insects multiply very fast in 
dry, hot weather, do not like strong air currents, 
and cannot stand cold water, especially applied with 
pressure. Syringing or spraying will help in their 
control. A spray of one to one and one-half level 
teaspoons of Colloidal or wettable Sulphur to one 
quart of water will be found very effective, and two 
sprays two or three days apart should clean up the 
infestation entirely. 
CUT WORMS are easily controlled by scattering 
about a teaspoonful of poison bran bait around the 
plant (but not touching it) as soon as plants are set 
or shoots appear from roots. The early evening is 
the best time to apply it. 
2 tablespoonfuls of molasses or brown sugar (dis- 
solved). 
1 level teaspoonful of paris green mixed in. 
Juice of an orange or equivalent in water. 
1 quart of bran or enough to make a reasonably 
dry mash. 
COMMON STEM BORER. This black-and-white 
striped worm when small enters the stem just above 
the ground ‘and usually works upward. It will be 
noticed in the early season by the shortening of the 
internodes and later on by wilting. When noticed 
early, cut the plant off near the ground and get the 
borer with your knife. If the borer is below where 
you want to cut back, use a hooked wire from the 
top. A plant cut back not later than July 15th 
should be in full bloom early in September. Wax, 
plaster paris or cellophane may be used to fill or 
cover the opening in the stem after borer is out, 
so water will not get in and rot the plant. 
Should a plant be too large to cut back when bor- 
er is discovered, use pyrethrum soap at strength of 
8 teaspoonfuls to gallon and inject with ear syringe. 
This will kill the borer or drive it out. Drain stalk 
out by slitting at the bottom to prevent stem rot. 
EUROPEAN CORN BORER. This is a serious 
pest when infestation is heavy. This borer when 
very small enters just above the leaf bracket and eats 
out the inside of the node, weakening it so the first 
storm snaps off the stem. All weeds, corn or dahlia 
stalks should be either destroyed or dug in before 
May Ist as a precaution. 
The U. S. Dept. of Agriculture Bureau of Ento- 
mology and Plant Quarantine of Washington, D. C. 
has accomplished much in research and development 
of control methods, and will forward you bulletin on 
Protection of Dahlias from Infestation by the 
European Corn Borer on request. 
The New Jersey Agricultural Experiment Station 
of New Brunswick, N. J. has issued a bulletin on 
Protecting Dahlias from Corn Borer Injury which 
will be mailed on request. 
FOR CORN BORER DUST made according to 
U. S. Dept. of Agriculture formula, see page 48. 
STUNT. In all our years of experience with dah- 
lias, we have dug and destroyed all unhealthy stock, 
and the results are most gratifying. This is properly 
