Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-05-24
THIS AND THAT
BY CHARLES E. TRACEWELL.

| Almost all such owners are worried,
from time to time, by the appearance
Of diseases in their pet bushes.
At this particular time the one pre-
vailing rose blight is the dreaded black
! spot, which appears upon the leaves,
causing them to turn black, then yellow,
and finally TO drop of.
! A rosebush no more than any other
plant can live without leaves. Even
weed, If shorn of Its leaves regularly,
will finally die at the root. This prac-
tice of deleaving weeds ultimately will
rid any lawn OF them. In painless
| slightly manner, without any OF the UNI
sightliness attending digging them up
| by the roots.
| The leaf system of the rosebush Is
even more important. since its pumping
action not only draws up the water and
nutriment from the soil, but also par
ticipates in the handling of the light
rays, from which results the green OF
| the plant and the color of the blossoms.
| Without healthy leaves no rose plant
| will do either its best or its halfway
| best; 1t will simply struggle along, trying
| to grow, but remaining the same height
year after year.
How many rosebushes do you know
| like that? Perhaps you have several IN
your own yard, and you say you have
no luck with roses. Examine the bushes
carefully and the chances are that you
| will find scores of black spotted leaves.
This is the dreaded black spot" and
rose growers great and small have real
cause to fear it, for it not only spoils
the appearance of the bushes, but
dwindles the number and size Of the
blossoms and in the end kills the plant.
~ 4 y
Black spot is a fungous disease and
its spores thrive and wax in gloomy, wet
weather.
Spraying either with liquid or powder
fungicides is the only remedy known to
date, and rainy weather, such as has
prevailed during the past month, makes
it far from sure one.
The trouble is that the water washes
off the powder or spray almost as soon
as it is put on, and the average gar
dener is inclined to spray all too infre-
quently anyway.
The result is that before the owner is
aware of it the insidious spots make
their appearance. Once on leaf, it Is
almost 'goner." All rose growers ad-
wise pulling off infected leaves and
burning them to prevent the spread of
the disease.
Ordinary bordeaux mixture is an old
standby and there are various other
sprays, particularly of copper and ar
senic, which are used to combat the
evil. Dusts made Of finely ground sui
phur are helpful.
1t is interesting to note that our two
big bushes. which get the sun all day
long and water almost never. have been
absolutely free from black spot. No
doubt the maximum of sun ION the
south side of the house, has an anti
septic action on the foliage.
There may be also some obscure re-
lation between available water and
black spot. Bushes which stand in a
bed not so well drained suffer more
than those in an adjacent bed at a
slightly higher level.
1t is not beyond the bounds of posi-
bility that the surplus water might help
convey the scourge through the system
of the BUSH to break through the thin
leaf surfaces as a sort of eruption.
Flower beds built higher than the
surrounding ground are wrong In theory
and practice in the great majority of
cases, but perhaps with rose beds the
procedure might be worth trying.
Since even the experts know little
about black spot, we unhesitatingly offer
this as an interesting speculation.