Crabgrass Control

Crabgrass is an annual grassy weed. Although it is hard to control after you notice it to be a prolific problem, it is relatively easy to prevent. All crabgrass preventers use the same strategy. They set up a chemical barrier in the soil that either stops the seed from germinating or kills the seed upon germination.

To get the most effective control, the chemical barrier needs to be in place at the time of germination. When is that? Crabgrass germinates when the soil temperatures reach 50° to 52°F and maintain that temperature for two to three days.

The chemical barrier when initially applied to the turf (usually in a granular form) needs time and moisture to set up. A slight precipitation is required to move the chemical from the granule into the soil. The soil then bonds to the chemical and surrounds the ungerminated seed.

Some things to consider:

• Do Not apply to areas that will soon be seeded. Crabgrass preventers will also inhibit grass and other seeds from germinating.
  
  
• Many crabgrass preventers will quickly deteriorate in wet soils especially after relatively heavy rainfalls.
  
  
• Micro climates may effect germination times relative to reported daily soil temperatures. For example, soil in shaded areas, especially on north facing slopes, will remain cooler for an extended period of time. Soil on south facing slopes and on south sides of dark colored buildings will warm up much faster.