Common Lawn Weeds and How to Get Rid of Them

How to Kill Common Lawn Weeds
Even the best-tended lawns come under attack from common weeds. Weed seeds float in on the wind, creeping weeds claim more territory, and weeds you thought you pulled quietly continue to grow. How well your lawn copes with the onslaught depends on the weeds involved, the response you choose and your lawn’s overall health. Understanding common lawn weeds and the options available to fight them can help you successfully combat the invasion.

To help simplify weed defense, we’ve charted 10 common lawn weeds, including their characteristics, type and how they spread, and most importantly- how to eliminate them. Weeds, like ornamental garden plants, can be annuals or perennials. Annual weeds, such as crabgrass, complete their entire life cycle in a single growing season, and then die, leaving seeds behind to continue the legacy. Perennial weeds, such as dandelions, come back year after year from their roots, and distribute new seeds to boot. Weeds can also be grass-like,broadleaf or sedge. Choosing the right weed control product requires understanding the weed you want to fight and its stage of growth. Pre-emergent weed controls, sometime called preventers, work to keep weed seeds from germinating and developing. Post-emergent weed controls fight weeds that have already germinated and emerged from the soil.

Plantain

Characteristics:

  • Broad leaves with five prominent veins running from the base
  • Short, winged leaf stalk
  • Dense, erect flower spikes

Weed Type:

Broadleaf perennial with shallow, fibrous roots.

How it Spreads:

By small, angular seeds. The mature seeds in one spike will range in color from orange all the way to black. Spikes will include seeds in shades of brown between the two extremes.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • Pennington UltraGreen Southern Weed and Feed 34-0-4
  • Lilly Miller® Moss Out! 5 in 1 Broadleaf Weed & Moss Killer
  • IMAGE® Kills Nutsedge

Dandelion

Characteristics:

  • Serrated, comb- and tooth-like leaves 
  • Hollow, leafless stalk
  • Yellow, petal-like flowers mature to white puffballs

Weed Type:

Broadleaf perennial with a long, deep taproot.

How it Spreads:

By seeds that germinate year-round in accommodating climates.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • Pennington UltraGreen Southern Weed and Feed 34-0-4
  • Lilly Miller® Moss Out! 5 in 1 Broadleaf Weed & Moss Killer
  • IMAGE® All-In-One Weed Killer 
  • IMAGE® Kills Nutsedge

Crabgrass

Weed Name:

Crabgrass

Characteristics:

  • Flat, pointed, narrow leaves, rolled at the base with a prominent midvein
  • Short, flat, purplish-green stems
  • Fringy, spike-like flower heads

Weed Type:

Annual summer grass that germinates throughout the season, capable of producing 150,000 seeds per plant, per season.

How it Spreads:

By seeds and lower stem pieces that root.

Controls:

Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III 30-0-4

Yellow Nutsedge

Weed Name:

Yellow Nutsedge

Characteristics:

  • Grass-like leaves, v-shaped in cross-section
  • Erect, hairless, triangular stems 
  • Golden-brown flower spikelets

Weed Type:

Perennial sedge that forms dense colonies.

How it Spreads:

By seeds and rhizomes, but primarily by underground tubers known as nutlets.

Controls:

  • IMAGE® All-In-One Weed Killer
  • IMAGE® Kills Nutsedge

 

Thistle

Weed Name:

Thistle

Characteristics:

  • Prickly, deeply-lobed leaves
  • Slender, hairless stems 
  • White, purple or pink flowers

Weed Type:

Broadleaf with many annual and perennial species and seeds that remain viable for many years.

How it Spreads:

By seeds and root fragments.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • Lilly Miller® Moss Out! 5 in 1 Broadleaf Weed & Moss Killer

Quickgrass

Weed Name:

Quickgrass

Characteristics:

  • Upright, flat, rough-edged, blue-green leaves
  • Leaf blade grasps the stem at its base
  • Flattened spike of alternating flowers and seeds

Weed Type:

Perennial grass most active during cool spring and fall seasons.

How it Spreads:

By seeds and rhizomes, but primarily by underground tubers known as nutlets.

Controls:

  • IMAGE® All-In-One Weed Killer
  • IMAGE® Kills Nutsedge

Oxalis (also known as creeping woodsorrel)

Weed Name:

Oxalis

Characteristics:

  • Heart-shaped leaflets, often purplish, occur three per leaf and fold down in heat 
  • Hairy, upright stems
  • Bright yellow spring flowers

Weed Type:

Broadleaf perennial with a shallow taproot and fibrous, expansive root system.

How it Spreads:

By creeping stems, extensive roots, pointed seed capsules that expel seeds, and root and stem fragments.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • Lilly Miller® Moss Out! 5 in 1 Broadleaf Weed & Moss Killer
  • IMAGE® All-In-One Weed Killer
  • IMAGE® for St. Augustinegrass & Centipedegrass

Common Ragweed

Weed Name:

Common Ragweed

Characteristics:

  • Hairy, fernlike, deeply-lobed leaves
  • Coarse, hairy stems
  • Inconspicuous, green-yellow flowers

Weed Type:

Broadleaf annual (responsible for hay fever) with shallow, fibrous roots.

How it Spreads:

By seed, with a single plant producing up to 60,000 seeds or more per season.

Controls:

Pennington UltraGreen Weed and Feed 30-0-4

Purslane

Weed Name:

Purslane

Characteristics:

  • Thick, purple-green, succulent leaves
  • Succulent, branching stems
  • Small, yellow flowers

Weed Type:

Broadleaf annual that develops thick, multi-branched mats.

How it Spreads:

By brown and black seed and stem fragments.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • IMAGE® All-In-One Weed Killer

Ground Ivy

Weed Name:

Ground Ivy

Characteristics:

  • Rounded, scalloped leaves
  • Four-sided, mint-family, squared stems 
  • Small, funnel-shaped, purple flowers

Weed Type:

Broadleaf, mat-forming perennial with a distinctive odor when crushed.

How it Spreads:

By seed and above-ground runners, known as stolons, that root at the nodes.

Controls:

  • Pennington UltraGreen Weed and Feed 30-0-4
  • Lilly Miller® Moss Out! 5 in 1 Broadleaf Weed & Moss Killer
  • IMAGE® All-In-One Weed Killer

Weed-Control Options

When choosing weed-control products, take into consideration your target weeds, whether they’re still seeds or emerged plants, and the type of lawn grass you grow. Different types of weeds call for different controls, and some Southern lawn grasses, such as St. Augustinegrass and Centipedegrass, are sensitive to some weed-control products. Always check the label to make sure the product you choose is suitable for your lawn grass. 

A top-notch weed-management program involves the following types of weed control products*:

  • Crabgrass Preventers: Crabgrass plants die after setting their seeds, but their seeds live on. Germination starts in spring, once soil temperatures reach approximately 55 degrees Fahrenheit – the same temperature that sends forsythia shrubs into bloom. Proper weed management works to stop those seeds from germinating and rid your lawn of any that sneak through. Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III 30-0-4 inhibits germination and root development of crabgrass and stops many weed grasses and broadleaf weed seeds when applied in early spring, before weed seeds germinate. While controlling weeds for three to five months, this nitrogen-rich product continues to feed your lawn. Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III 30-0-4 prevents crabgrass germination, suppresses other weed grass and broadleaf weed seeds and controls weed grass for three to five months while feeding your lawn with slow-release nitrogen.
  • Weed & Feed Fertilizers: As the name implies, weed & feed products tackle common lawn weeds while feeding lawn grasses to better help them act against weed invasion. Pennington UltraGreen Weed & Feed 30-0-4 and Pennington UltraGreen Southern Weed & Feed 34-0-4, both safe on Centipedegrass and St. Augustinegrass lawns, kill and suppress tough existing broadleaf weeds and control new weeds for up to three months in established lawns. Applied when weeds are actively growing in late spring and early summer, and again in early fall, these weed & feed products continue to feed your lawn grass and keep it beautiful and green.
  • Targeted Weed Control: When existing perennial weeds continue to be a problem, or when new weed seeds germinate and seedlings emerge, a targeted post-emergent herbicide is the answer. For best results, treat weeds while they’re small and actively growing throughout the season. IMAGE All-in-One Weed Killer herbicide offers a broad spectrum of selective weed control for difficult sedges, crabgrass and broadleaf weeds, killing weed roots, shoots and nutlets. These weed killers target weeds only and are suitable for most cool- and warm-season lawn grasses. IMAGE Kills Nutsedge and IMAGE Herbicide for St. Augustinegrass and Centipedegrass provide targeted, selective control of tenacious, emerged weeds.

Well maintained lawns naturally control weeds.

Keeping your lawn grass healthy and competitive provides the best defense against lawn weed invasions. Follow these four steps to a healthier, stronger lawn:

1. Always mow at the recommended mowing height for your type of lawn grass. This helps promote healthy root growth and increases resistance to pests and disease.

2. Mow based on grass growth, not your calendar. Time your mowing so you remove roughly one-third of the length of the grass blades in a single mowing.

3. Supplement natural rainfall by irrigating your lawn as needed. Proper watering provides an average lawn with the equivalent of about 1 inch of rainfall each week. This allows moisture to penetrate deeply and encourages healthy, deep root growth. Watering only once or twice per week is better than more frequent watering. 

4. Keep your lawn well-fed with quality weed & feed or fertilizer-only products, such as the Pennington UltraGreen line of lawn fertilizers.

*Always consult the product label for your specific lawn grass type before using any type of weed control products.

Pennington is a trademark of Pennington Seed, Inc. Alaska, Lilly Miller, Moss Out!, Image and UltraGreen are registered trademarks of Central Garden & Pet Company.