Quackgrass and Crabgrass
Nature Bulletin No. 380-A May 2, 1070
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
QUACKGRASS AND CRABGRASS
Quackgrass is one of the pesky weeds that are benefited by the foolish
practice of annually burning the dead vegetation on vacant lots and on
meadows in outlying subdivisions. Its vigorous root systems survive
and spread until it replaces the good grasses, clovers and other
desirable plants which are destroyed by such fires. Many people
confuse quackgrass with crabgrass.
Quackgrass is a perennial and a member of the Barley Tribe. Native in
Europe, it appeared in Connecticut about 1750. Now it infests most of
our northern states and southern Canada because, before it was
designated by law as a noxious weed, its seeds were often carelessly
included with those of bluegrass and timothy. Being adapted to a cool
climate, it is not found in the southern states nor the southwestern
Quackgrass sends up long slender stems with flat narrow leaves and is
sometimes mistaken for timothy. The seed head, however, is more like
that of wheat and western wheatgrass; and it sends out long
underground runners with knot-like joints. Branches develop at many
of the joints and those may branch again. At any joint, fibrous roots
may develop and a leafy stem push up through the ground to become
another plant. Thus it spreads both by its seeds and its root stocks --
called "rhizomes" -- and, even when these are chopped up by a farm
implement, each joint left in the soil may sprout roots and grow.
Quackgrass is so hard to kill that it has many harsh names such as
Witchgrass and Devil's Grass. The most effective means of control
appears to be spraying with a liquid chemical that has a long name
abbreviated to "TCA".
Livestock will eat the new tender quackgrass in early spring; and in
North Dakota, for instance, some farmers cut two crops of quackgrass
hay each year; but it is poor feed and we understand that many
thousands of acres have been abandoned as grazing lands because of it.
The best thing to be said for the plant is that it is an excellent
soilbinder on slopes and sandy ground subject to erosion.
Crabgrass, an annual and a member of the Millet-Tribe, is another
European plant that has become one of the worst pests in gardens,
lawns and golf courses of the East, Middle West and South. It is one of
the fastest-growing weeds and spreads not only from its seeds but also
from its branching stems which sprawl on the ground and take root at
the joints. In late spring, when the plants are young, they can be easily
pulled up and destroyed but later this becomes a chore and, if one tiny
root is left in the ground, the plant will grow and re-establish itself. As
we say of a cat: "It has nine lives".
The two principal species of crabgrass and their several varieties are
also known as Summer Grass, Finger Grass and by other descriptive
names. The large species has thin leaves from 3 to 6 inches long, and
a half-inch or less in width, which are rather hairy. The seeds are
borne on a cluster of from 3 to 5 spikes, like fingers, at the tip of the
seed stalk. Since this, too, may lie almost flat and be missed by a lawn
mower, vigilance is required to prevent crabgrass from reseeding
itself. The smaller species is similar but the leaves are not hairy. Both
may be controlled by spraying or dusting with various chemicals but
potassium cyanate is now generally recommended, for home owners,
because it is nonpoisonous, cheap and easy to apply.
Crabgrass has some value as a forage plant and in parts of Europe it is
cultivated for its seeds which, cooked in milk, like sago, are highly
Sprinkled over quackgrass leaves, that might be a tasty dish -- for a goat.
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Update: June 2012