The evening times., 1900-03-15
No. 623 18th St.N.W
BAD BFFEC9S OF Weeds
An Expert Talks on Their Aceumu
latiOn on City Lots.
Useful i'm Absorbing Poisonous Gases
ntii They Begin to Decay-Rank
Vegetation UnhenIthfuI-Its De-
StructiOn should he Accomplish
ed Under Municipal Direction.

Lyster Il. Dewey Assistant B0r8nist in
the Department OF Agriculture. has made
special study OF weeds in cities and
towns and furnishes some interesting OBJ
servstiOns on this subject
In all cities and villages there are va
can't lots awaiting purchasers. ne says.
'and in many agricultural districts the
unused land in towns often exceeds in pro-
portion the unused land IN the surround
ing farms. These vacant lots are held in
expectation that they Will be used same
time for building sites. and until build
ings are erected upon them they are usu-
ally given up 10 whatever viii grow. While
unused land in the country Is generally
covered with native vegetation that iR
cities and towns has usually al some time
been under cultivation so that the native
vegetation has been destroyed. and It's Sit
nation is such that it is most readily seed
ing with migratory weeds. The seeds are
introduced in the packing Of cEozkery. the
sweepings from stores rubbish from yards.
cleanings from stables and stock car. and
In various kinds Of garbage and refuse. too
commonly deposited on vaCanI lufs Tnc
conditions for weed production. have been
most admirably prepared. and the natural
result is a plentiful crop
In commenting on the chsra -teristi-s Of
city weeds. Mr.. Dewey said.
The weeds OF cites and villages are
usually Of the migratory class. cosmopoh-
tan in character, and capable Of thriving
under a wide range Of environment Ac-
cordirg to the early European works On
botany, plants from Asia. adventiye in Eu-
rope. usually appeared first in cities. Many
Of these plants are now found about the
cities and towns Of this country. Others
are native plants which have withstoo4
the changed conditions due TO cultivation
and have acquired a wced-like habit In
the Eastern cities and in those on the Pa
cihc Coast Old World species predomiuate
while In the cities OF the interior espa-
cially in those west of the Missi-sipri
River. there is . larger proportion of na-
tive plants. The species vary I'M diH, -cnr
cities IL different years and in dinerrrt
seasons.
The wild onion Of winter and carly
spring in this city is followed By the dan
delion and bulbous buttercup: then come
the Wild carrot PTiCkly lettuce and svee.
clover, and these in turn are partly Gis-
placed in the fan by holseWead. ragwceI
cccklebuT, Mexican tea. slender pfgweed
and jimson weed. chicory. horse cocI, e.
burr wild heiiotroDe, milk thistle a-d tar
weeds
Mr.. Dewey spoke OF the uses of weed, in
cities as follows:
The weeds growing within easy reach
OF pupils and teachers in city schools fur
nish some material for botanical studies
Birds find in weed seeds a considerable
portion OF their food supply. and some
times make their nests in the larger
weeds; but cocheburs. burdock. thistles
ragweeds. aud other coarse species might
well be replaced by seed bearing grasses
and cloveTs. which are better liked by
seed-eating birds.
Growing weeds like other plants Du-
rify the air. and herein lies the chief ben
eft conferred by their presence in cities
where numerous fires in dwellings facto
ries. and locomotives. and the breathing
Of the people continually rob the air of ite
oxygen and charge it with carbonic-acid
gas. Growing plants. weeds as well as
others. reverse this process They with
draw from the air carbonie-acid gas ana
sometimes other injurious gases. and give
of oxygen, thus tending to purify the air
and keep it supplied with the most essen
tisl element"
Mr.. Dewey next spoke OF the bad er-
fects OF weeds which. he said, were but
little known.
The injuries resulting from the pr. $
enee Of weeds outweigh many times all
the good that can be ascribed to them" be
remarked. They harbor injurious insects
and iuEgous aud bacterial diseases OF cuI- I
tivated plants. Many insects injurious to
garden and ield crops also live on weeds.
upon which they thrive and multiply. and
thus keep UP their numbers ready to at
tack their favOrite cultivated crop as sOOp
as 1t is left unprotected The control n
insect enemies and fungous and bacterial
diseases Of field and garden crops is rem
3ered much more difficult and their exter-
in some instances, is made prac-
ucaliy impossible, because they exist on |
weeds that are not sfbjec- TO the care be- !
slowed on cultivates crops
While weeds are growing they aid in
the air, but when growth stops !
and they begin TO decay their effect is Just
The opposite. They then absorb oxygen |