Minnesota Weeds

Controlling Grass Weeds
http://www.extension.umn.edu/distribution/horticulture/DG1137.html

Grass Weeds
Annual bluegrass (A, P) Barnyardgrass (A) Crabgrass (A) Foxtail (A) Goosegrass (A)	Use preemergence herbicides. Apply two to three weeks prior to expected germination of weed seeds. Some of these herbicides may injure fine fescues or bentgrasses. Most preemergent herbicides will harm newly seeded grasses except siduron (Tupersan).
Bromegrass (P) Quackgrass (P) Tall Fescue (P) Creeping bentgrass (P)	These weeds can be controlled only with nonselective herbicides. Spot treat only because herbicide will also kill desirable grass plants. Apply when weeds are actively growing.

Quack Grass - Not Crab Grass

Illustration: Weeds of the North Central States

http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/h507quackgrass.html

Quackgrass--Agropyron repens--is a perennial weed in Minnesota, and a troublesome weed to eliminate from the home landscape. The Latin name means a 'sudden field of fire', and attests to its ability to take over lawns, fields and gardens. The plant is hardy to zone 3 and is actually native to Europe. It has been growing in the U.S. for over 200 years in all states except Hawaii, Arizona and Florida.

In older books quackgrass may be referred to as couch, quitch, devils, wheat, scutch, twitch, witch, dog or durfa grass. This plant is listed in 41 states as a noxious weed because of the detrimental effects it has on agricultural crops, though it does help control erosion.

In the home garden, quackgrass can invade gardens containing perennial flowers or vegetables, making it extremely difficult to eradicate. This sheet will discuss both chemical and non-chemical methods to control this weed in gardens.

An understanding of how the quackgrass grows will help avoid common errors in battling this plant. Quackgrass grows from underground rhizomes to an unmowed height of 1 to 4 feet. It has thin, flat, bright ashy green leaf blades. The seed spike grows from 3 to 8 inches long and appears in July. Quackgrass seed is often found in rye straw, so you may want to avoid using this as mulch in your garden. Each quackgrass plant produces about 25 seeds; they remain viable 3 to 5 years in the soil. It takes 2 to 3 months for a newly germinated plant to develop rhizomes. It is very important to eliminate the plants before they reach this stage.<snip>

Recommends selective use of roundup