Types

• Crabgrass belongs to the genus Digitaria, and family Poaceae. This type of grass is also known as finger-grass and fonio. The most common species of crabgrass in North America are Large Crabgrass and Smooth Crabgrass. These are usually considered weeds and can be a serious lawn pest. Crabgrass is a plant with wide, flat leaf blades and spreading stems. Large crabgrass tends to be mat forming. It can reach a height of over 3 feet and will often have purple stems. Smooth crabgrass is much smaller and tends to gown no more than 15 inches in height.
  
  

Time Frame

• Crabgrass is especially proficient at taking over lawns that are growing thinly in unfertilized, poorly draining areas. One plant can easily produce 150,000 seeds each season, quickly overtaking domesticated lawn grass. Crabgrass will also spread in empty areas of lawn and gardens. Crabgrass seeds typically germinate in late spring and early summer, though in many climates, the seeds can germinate year round.
  
  

Prevention/Solution

• The most common question posed in reference to crabgrass is how one can get rid of it. The easiest way to get rid of crab grass is by using pre-emergent herbicides. These herbicides need to be applied just before germination, and should prevent seedlings from emerging. In general, this type of herbicide should be applied when local forsythia blooms begin to wilt. Another type of herbicide available for dealing with existing crabgrass is post-emergent herbicide. However, this will only kill young plants and tends to be much less successful than pre-emergent herbicide.
  
  

Considerations

• One frequently overlooked method of dealing with crabgrass is to simply prevent it, rather than spend time and effort dealing with existing plants. A well maintained lawn will prevent crabgrass and other weeds from getting the foothold they need. Lawns should be fertilized most heavily in autumn, and consistently watered. Crabgrass grows very shallowly, so be sure to water deep into the soil. Another way to prevent crabgrass organically is to let your lawn remain at a height of around 2 or 3 inches, allowing the grass to protect itself.
  
  

Benefits

• Crabgrass usually gets a bad reputation as a pesky weed. However, crabgrass does have several redeeming qualities. Crabgrass seeds can be toasted and ground into flour. This flour is used for porridge. The seeds can also be fermented to make beer. In some parts of Africa, crabgrass is a staple crop. Crabgrass can grow in both hemispheres in a variety of climates including temperate, tropical and subtropical areas.