INDIVIDUAL WEEDS— CRAB GRASS 9 



and plant drawings were made by G. D. George, Walter S. Beach, 

 and O. F. Illescas. For the seed drawings the authors are greatly 

 indebted to F. H. Hillman, of the Seed Laboratory of the United 

 States Department of Agriculture. 



INDIVIDUAL WEEDS 

 Crab Grass (Syntherisma sanguinalis L. Dulac) 



Other common names. — Large crab grass, ringer grass, Polish 

 millet, hairy finger grass, crow foot or pigeon grass. 



Description. — Crab grass is an annual, spreading plant, usually 

 growing very close to the ground. Its creeping stems are sometimes 

 from one to three feet long. This grass was introduced from Europe 

 and is now found throughout this State, except possibly in the ex- 

 treme north. It is quite common in cultivated fields and along road- 

 sides but is particularly common in lawns, where it is one of the 

 worst weed grasses. The plant flowers in early autumn and does not 

 mature its seeds until late in August or early in September, so it is 

 particularly troublesome in the latter part of the season. The leaves 

 are generally quite hairy and vary from two to six inches long and 

 often have a very reddish hue. The flowers and seeds are arranged 

 on long, finger-like branches suggesting the name finger grass. These 

 branches are sometimes nearly purple in color. The plant is propa- 

 gated almost entirely by seed, although sometimes roots spring from 

 the joints of the stem. The seeds of crab grass are about a tenth 

 of an inch long, generally straw-colored or a dull, purplish green. 

 They are convex on one side and nearly flat on the other. Seeds of 

 crab grass are frequently found in lawn-grass mixtures and in seeds 

 of redtop and Kentucky blue grass. 



Eradication. — Prevent the plants from going to seed by cutting 

 early and often throughout the season. Owing to the spreading 

 habit of the plant, it is difficult to cut all of the seed stalks with the 

 lawn mower. Hand work with a sickle or scythe is often necessary 

 to complete eradication. Where only a few plants appear in a lawn 

 they should be dug out or pulled as soon as recognized. Thin spots 

 in the lawn should be thickened up by sowing some Kentucky blue- 

 grass seed. Keeping the lawn in good condition by top-dressing occa- 

 sionally will help also in keeping out crab grass. Little trouble is 

 experienced with this weed in cultivated fields. The above treatment 

 will not completely eradicate crab grass, but will hold it in check as 

 much as possible. 



