How Do Crabgrass Seeds Spread?
Crabgrass, also known as crow foot, Polish millet, Digitaria or by assorted profanities, was brought to North America by the United States Patent Office in 1849. Intentionally expected to provide forage for cattle, crabgrass rapidly spread across the country. Crabgrass is a fecund and invasive plant that has become the bane of crop growers and gardeners. Does this Spark an idea?
-
Life Cycle and Reproduction
-
A single crabgrass plant may produce up to 150,000 seeds. Seeds germinate as soon as soil temperature consistently reaches 60 degrees F, which is early spring for most areas of North America. The very low, broad, spreading habit of the plant ensures that crabgrass survives most mower depths and permits a wide radius for successful seed distribution.
Seeds Spread Via Mowing
-
Crabgrass is more prolific than other weeds because it is able to produce seeds below the typical mowing depth of most lawn movers. Moreover, seed dispersion is encouraged by the wind-producing, whirling blades and the movement of the mower tires over the plant. Horticulturalists recommend that lawns be mowed to a height of 2 to 3 inches, to allow turf grass to grow over the crabgrass for shade. Crabgrass dislike cool conditions, and seeds are less likely to germinate under such conditions.
-
Seeds Spread Via Wind
-
Most plant seed dispersal is with wind, and crabgrass is no exception. Crabgrass seeds rarely travel long distances, but the seeds germinate and grow so quickly that an entire lawn can be overrun very quickly. Activities such as haying or mowing may stir up the plant and disperse seeds into a breeze or wind current. Crabgrass along sides of roads find the highway wind currents a perfect medium for seed transportation.
Seeds Spread Via Physical Transport
-
According to researchers at Mississippi State University, the primary method of crabgrass seed dispersion is human activity. Seeds may cling to clothing or to transportation cargo such as hay bales and nursery plants. In addition, birds and roaming animals may unwittingly carry and disperse crabgrass seeds as they travel, migrate or relocate to newer food source locations.
Seeds Spread Via Water
-
Gently flowing streams or rapidly raging floods carry seeds wherever they go. Crabgrass seeds are extremely hardy. Seeds may lie dormant for decades, waiting for a suitable environment and warm temperatures. Moreover, flooding often carries away important nutrients and turfgrass, leaving behind poor soil and vulnerable soil--conditions that pose no complications to the prolific and unfussy crabgrass plant.
-
References
- Photo Credit field of dried weeds in summer image by Sherri Camp from Fotolia.com
