Grassy Weeds

To the untrained eye, distinguishing turf grass from grassy weeds is tough because the two can look identical, but we’ll help you weed out the weeds. With practice and persistence, you can learn to identify lawn weeds—and even the difference between grass and sedge—by inspecting the primary vegetative characteristics of your lawn.

Here are some of the features our TruGreen® experts use to weed out the bad grasses:

• Crown: The white, thick part of the grass plant at soil level where the shoot meets the roots.
• Sheath: The lower portion of the grass leaf between the crown and the blade that encloses and protects young shoots of grass.
• Collar: The backside of a leaf where the blade and sheath join. Collars may be divided by a line that runs up the center or be continuous.
• Blade: The section of the leaf above the collar. Characteristics to look for include the type of tip, roughness or smoothness, and mid-rib.
• Vernation: The leaf arrangement of the youngest leaf (called the budleaf) and its surrounding sheath. Look to see if the budleaf is rolled or folded.
• Ligule: A tip or cylinder-shaped structure poking out from the top half of a leaf where the blade and the sheath join. Ligules can be membranous, hairy, both or absent altogether.
• Auricle: A pair of appendages sticking out from the side of the grass leaf where the sheath and blade meet. Auricles can be short and stubby, large and claw-like, have short hairs attached or be absent.
• Rhizomes: An underground stem that produces a new plant.
• Stolons: A horizontal, above-ground stem that roots at the nodes (found in the crown) and gives rise to new grass plants.
• Seed head: The flowering or seeding parts found at the top of the grass plant. Check if seed heads are spike or panicle to help with turf grass identification.

Understanding the varying life cycles of grassy weeds is key to getting rid of them. Learn what the different life cycles of lawn weeds mean for your control plan.

• Annual weeds live for only one season and are typically easy to control because they lack the complex underground structures needed to spread new plant growth through creeping roots. Still, annuals produce tons of seeds that can infest and dominate your yard under the right conditions.
• Summer annuals begin to grow in the spring, mature in the summer, and then produce seeds and die by the fall or first hard frost—an entire life cycle completed within 12 months.
• Winter annuals overlap two calendar years but last only 12 months total. They germinate and develop from late summer to early fall, remain semi dormant during the winter and then flower in spring. Come late spring or early summer, they mature and die off as the weather warms.
• Perennial weeds can germinate and spread from seeds, but they also produce a root structure that can birth new weeds from your lawn’s surface or from underground.
• Biennial weeds generally live for two years. The first year consists of leaves, stems and root growth, followed by winter dormancy. In the second year, biennials flower and produce seeds, completing their life cycles.

Without a professional service, it's tough to eradicate grassy weeds without harming your lawn due to their biological similarities, so prevention and targeted treatments are key. For example, spraying crabgrass killer at the wrong time can kill your grass seeds. Instead, aim to control grassy weeds by keeping your lawn dense and healthy so they don’t stand a chance. If these turf grass imposters have already invaded your lawn, you can try a few other tactics to weed them out.

Defending With Lawn Health

The most effective weed control is a flourishing lawn because it’s more competitive and will crowd out grassy weeds. Weed seeds need light to grow, which a dense lawn blocks out. To keep your lawn lush, healthy and competitive, try:

• Fertilization: The right type and application method makes all the difference.
• Mowing: Done frequently at the recommended height with sharpened blades.
• Watering: When rainfall is scarce, water deeper rather than more frequently.
• Grass Selection: Factor in climate, sunlight, shade, etc., to pick the right turf grass.

Pulling Weeds

Hand-pulling grassy weeds can work if there are only a few, especially if they’re annuals. Perennial grassy weeds are harder to control by hand because you don’t always pull up the vegetative structure, which is what sprouts new weeds.

Herbicides

• Post-emergence herbicides control existing weeds. Unfortunately, because grassy weeds are in the same family as turf grass, these types of herbicides can also harm your lawn.
• Pre-emergence herbicides control seeds only—not existing weeds—making them safer for an established lawn. They work on most seed-based annuals and perennials.

The plan of attack depends on your region, type of turf grass and the specific weeds invading your lawn