What Is Biennial Grass?

Weedy

• Biennial grass is considered a weed unless it is planted on purpose. Soft brome (Bromus mollis) is a biennial that's also known as soft chess. This grass grows 12 inches high when mature. The thin leaves and stems are covered with soft, downy hairs. This type of biennial grass grows along dry roadsides and in waste places in the wild.

Seasonal

• Most biennial grass completes its life cycle in a single year, but the plant treats the change in season as individual growing seasons. Italian ryegrass (Lolium multiflorum) is an upright biennial grass that grows strongly during the winter and in the early spring. The hairless stems reach 36 inches tall. The flowers or panicles appear from April through September when the weather is warmer. The shiny ryegrass seeds sow themselves to start the life cycle over again.

Cool Season

• Some biennial grass types stop growing when the weather turns hot. Bluegrass (Poa annua) grows best during the cooler weather of the year. This variety of grass produces clumps of hairless leaf blades that are yellowish to dark green in color. Flowers top the 3- to 12-inch-tall stems from December until July. The seeds lay dormant until after the hottest of the summer weather.

Growing

• Remove all the weeds and debris from the planting area. This eliminates competition from weeds for resources in the soil-like moisture and nutrients. Till the soil until the dirt particles are smaller than sweet peas. Rake the planting area smooth. Broadcast the biennial grass seed and lightly rake it into the soil so only 1/4 inch of soil or less covers the seeds. Sprinkle the seeds with water and keep the seeds moist until the grass is growing strongly. If planting the biennial grass as a temporary ground cover, remove it before seeds develop.