Identifying 9 Common Lawn Weeds

Having a lush, green lawn is the desire of most homeowners. However, weeds can quickly invade and take over, creating an unsightly mess. Learning to identify the most common lawn weeds is an important step in maintaining a healthy and attractive yard. In this comprehensive guide, we will examine 9 of the most widespread weeds that plague lawns and provide tips for controlling them.

Crabgrass

Crabgrass is one of the most problematic weeds infesting lawns across North America. Here are some key identifying traits of crabgrass:

Light green in color with reddish-purple hues. The leaves have a coarse texture.
Grows close to the ground in a spreading, matted fashion. Sends out stems that radiate from a central root system.
Forms seed heads on finger-like spikes that stand upright above the foliage. The spikes turn purplish as seeds develop.

How to Control:

Crabgrass is an annual weed that reproduces by seed. Follow these tips to control crabgrass:

Apply a pre-emergent herbicide on your lawn in early spring before crabgrass seeds have a chance to sprout. This will prevent new growth.
For existing crabgrass, use a post-emergent herbicide containing quinclorac or fenoxaprop during summer when the weed is actively growing.
Improve the health and density of your lawn grass to discourage crabgrass from invading.
Hand pull small infestations before they have a chance to spread. Make sure to remove all the root system.
Overseed bare spots in the fall to crowd out any crabgrass.

Dandelion

Dandelions have delicate yellow flowers that turn into round cottony seed heads. Here are some traits to identify them:

Flowers and seed heads sit singly atop a hollow, smooth stem that contains milky sap.
Deep taproot with dark brown, irregularly-shaped leaves that are deeply lobed. Leaves form a rosette pattern low to the ground.
Seeds are dispersed by wind, spreading quickly to colonize lawns. Plants can regenerate from root fragments left behind.

Removal Methods:

Dandelions thrive in poor lawns that lack density and vigor. Try these removal techniques:

Digging up the taproot using a sturdy tool like a dandelion puller or screwdriver. Get as much root as possible.
Applying a broadleaf weed killer containing 2,4-D, dicamba, or MCPP for efficient chemical control during the growing season.
Crowding them out by improving light, soil nutrients, and proper mowing height to optimize grass growth.
Overseeding to prevent dandelion seeds from germinating in bare areas.

Broadleaf Plantain

Broadleaf plantain is often mistaken for a common lawn grass. Identify it by:

Thick fibrous stems with broad, oval-shaped leaves that grow in a rosette pattern. The leaves have parallel veins.
Leaves are light green and smooth with five prominent veins running their length. TheyJOIN end in a point.
Tiny greenish cone-shaped flowers on stalks that emerge from the base. Seeds form in capsules.

Management Tips:

Broadleaf plantain thrives in compacted, poor soils. Cultivate the lawn to control it:

Improve drainage and aerate compacted clay soils regularly to encourage deep root growth of desirable grasses.
Apply nitrogen fertilizer to help the lawn outcompete broadleaf plantain.
Use a post-emergent herbicide with dicamba or triclopyr to target broadleaf weeds.
Pull young plants by hand before they become established. Ensure removal of the taproot.
Overseed in fall and spring to fill in bare spots before broadleaf plantain invades.

Common Chickweed

Common chickweed is a persistent winter annual weed in cool-season lawns. Identify it by:

Delicate stems with fine hairs form dense low mats, rooting at the nodes. Spreads across lawns and bare soil.
Small oval leaves in pairs along the stem. Smooth edges with pointed tips.
Tiny white star-shaped flowers in clusters emerging from leaf axils and stem tips.

Tips to Remove Chickweed:

Chickweed thrives in cool, moist conditions. Try these organic methods:

Improve lawn drainage and reduce shade to discourage chickweed. It prefers wet, poorly draining soils.
Remove plants by hand, taking care to get all the stems and roots or it will regrow. Do not leave fragments behind.
Apply corn gluten meal in early spring to inhibit seed germination. Reapply every 6-8 weeks.
Increase mowing height to encourage grass to outcompete chickweed. Removing too much at once creates bare spots for reinfestation.
Overseed to fill in bare patches that are vulnerable to chickweed invasion.

Creeping Charlie

Creeping Charlie, also called ground ivy, forms a dense, carpet-like mat across lawns. Identify by:

Square stems that root at the nodes as they creep along the ground. Forms thick patches.
Kidney-shaped, scallop-edged leaves with a minty aroma. Leaves are paired along the stem.
Clusters of small bluish-purple funnel shaped flowers that bloom in spring.

Creeping Charlie Control:

Creeping Charlie thrives in shady, wet conditions. Here are some removal strategies:

Improve lawn drainage and reduce shade to discourage its spread. Avoid overwatering.
Apply triclopyr herbicide during active growth when temperatures are above 45°F. Repeat applications are likely needed.
Pull up plants by hand, ensuring you dig deep and remove all the root fragments so it doesn’t reestablish.
Overseed bald patches in the fall with grass seed to prevent reinfestation of bare areas.
Increase mowing height which encourages grass to outcompete creeping Charlie.

Wild Violet

Wild violet is a common perennial lawn weed identified by:

Heart-shaped leaves with scalloped edges. Leaves and stems emerge from the same point.
Irregular purple and white 5-petaled flowers bloom in spring. Flowers are edible.
Seeds form in round capsules while flowers fade, dispersing in all directions when capsules burst.

Wild Violet Management:

Wild violet thrives in shady lawns with poor drainage. Control methods include:

Improving lawn growing conditions by reducing shade, aerating compacted soil, and fixing drainage issues.
Applying triclopyr-based herbicide in early spring or fall when violets are actively growing for the best results.
Manually removing by severing the plant below the root crown with a sharp tool. ensure all root parts are removed.
Overseeding to crowd out violets as grass fills in bare patches.
Adjusting mowing height to favor lawn grass competitiveness over violets.

Purslane

Purslane invades lawn gaps and vegetable gardens. Identify by:

Succulent, reddish stems that radiate and form mat-like clusters close to the ground.
Smooth, paddle-shaped leaves clustered at stem ends. Alternate along the stem. Shiny green.
Tiny 5-petaled yellow flowers that later yield capsule fruits containing many tiny black seeds.

Purslane Management:

Stop purslane from spreading using these organic methods:

Hand pull to remove plants before they go to seed. Take care to extract all the root pieces.
Mulch garden beds to block light from reaching purslane seeds and seedlings.
Improve drainage in waterlogged areas. Purslane thrives in moist conditions.
-Apply corn gluten meal early in the season to inhibit seed germination. Reapply every 6-8 weeks.
Overseed lawns in fall to crowd out purslane. Increase mowing height to favor grass growth over purslane.

Ground Ivy

Ground ivy, also called Creeping Charlie, forms a dense, carpet-like mat across lawns. Identify by:

Square stems that root at the nodes as they creep along the ground. Forms thick patches.
Kidney-shaped, scallop-edged leaves with a minty aroma. Leaves are paired along the stem.
Clusters of small bluish-purple funnel shaped flowers that bloom in spring.

Ground Ivy Control:

Ground ivy thrives in shady, wet conditions. Here are some removal strategies:

Improve lawn drainage and reduce shade to discourage its spread. Avoid overwatering.
Apply triclopyr herbicide during active growth when temperatures are above 45°F. Repeat applications are likely needed.
Pull up plants by hand, ensuring you dig deep and remove all the root fragments so it doesn’t reestablish.
Overseed bald patches in the fall with grass seed to prevent reinfestation of bare areas.
Increase mowing height which encourages grass to outcompete ground ivy.

Yellow Nutsedge

Yellow nutsedge is a perennial sedge weed thriving in moist, poorly drained soils. Identify it by:

Bright green, grass-like leaves in a triangular shape coming from the base. Glossy yellow-green.
Golden yellow-brown flowers form in clusters on triangular stems. Blooms mid to late summer.
Thick rhizomes form chains of underground tubers that store energy over winter. Nutlets turn brown when mature.

Removing Yellow Nutsedge:

Nutsedge has an extensive underground tuber system making it difficult to control. Try these methods:

Improve lawn drainage and reduce irrigation to make conditions less hospitable for nutsedge.
Apply a post-emergent herbicide containing sulfentrazone or halosulfuron when actively growing in summer. Often takes repeat applications.
Regularly dig out tubers to weaken the underground storage system. Remove as many nutlets as possible.
Cultivate beds frequently to prevent dormant tubers from sprouting. Expose to light.
Use corn gluten meal as a pre-emergent in spring to inhibit seedling establishment. Reapply every 6-8 weeks.

Prostrate Knotweed

Prostrate knotweed is a low-growing summer annual weed. Identify by:

Forms a flat mat of stems radiating along the soil surface from a central root. Can quickly spread.
Small oval leaves are bluish-green with a blunt rounded tip. Arrange alternately along stem.
Minute greenish-white flowers in summer followed by tiny 3-sided winged fruits that cling to clothing when mature.

Prostrate Knotweed Management:

Prostrate knotweed thrives in thin lawns with poor soil. Remove it by:

Overseeding to crowd it out and fill in bare patches it would otherwise colonize.
Mowing regularly at a high setting to shade out young knotweed plants.
Improving soil nutrition and drainage to favor healthy grass growth.
Applying pre-emergent herbicides like dithiopyr early in spring before seeds germinate.
Manually dig up plants, taking care to remove all root fragments so it doesn’t regrow.

Oxalis

Oxalis goes by the nickname “wood sorrel” and its faintly lemon-flavored leaves. Identify it by:

Delicate clover-like leaves divided into three heart-shaped leaflets. Often folds or closes at night.
Thin creeping stems that root at nodes and send up upright flower stalks.
Bright yellow 5-petaled flowers resembling buttercups that bloom spring through fall.

Oxalis Control:

Oxalis spreads readily by seed and tiny bulbs. Use these removal methods:

Apply triclopyr herbicide when oxalis is actively growing for effective control. Repeat treatments are often necessary.
Improve lawn density by aerating, fertilizing appropriately, and overseeding bald areas.
Hand dig shallowly to remove as many of the small bulbs as possible. Thorough removal is difficult.
Use corn gluten meal as an organic pre-emergent herbicide to prevent seed germination. Reapply every 6-8 weeks.
Increase mowing height to shade out young oxalis plants. Adjust irrigation to favor grass growth.

Curly Dock

Curly dock is a common perennial weed identified by:

Grows as a basal rosette in spring before sending up flower stalks in summer. Taproot.
Oblong leaves 6-12 inches long with curly, wavy edges. Reddish veins and petioles.
Reddish-green flower stalks reaching 2-4 feet tall bearing clusters of small greenish flowers.

Curly Dock Management:

Curly dock thrives in poor, compacted soils. Control with:

Applying triclopyr herbicide when actively growing in spring and fall. Effective on broadleaf weeds.
Digging up the taproot using a dandelion fork or tool to pry up the entirety of the root.
Improving soil quality with aeration, amendments, and proper pH to favor lawn grass vigor over dock.
Covering plants with cardboard or a dark tarp to block light and starve the plant.
Overseeding bald spots so desirable grass fills the area rather than dock invading.

Lawn Weed Control FAQs

Below are answers to some frequently asked questions about controlling common lawn weeds:

What is the best time to spray weeds?

The best time is during active growth when temperatures are above 45°F – usually early to mid spring until first frost. Avoid mowing for a few days before and after herbicide application.

When should I apply pre-emergent herbicide?

Apply pre-emergent in early spring before soil temperatures reach 55°F and again 6-8 weeks later according to label directions. This targets weed seeds at germination.

What vinegar mixture kills weeds?

For an organic option, mix 1 gallon vinegar with 1 cup table salt and 1 tbsp dish soap. Spray weeds on a hot, sunny day being careful to avoid grass and other plants.

Will pulling weeds spread them?

It can if root fragments are left behind. Use a tool to remove the entire root. Also discard pulled weeds promptly and do not compost.

How do I stop weeds from going to seed?

Mow regularly, hand pull, or spot spray weeds before they flower and go to seed. Remove and destroy seed heads. Overseed bald areas.

What is the most effective lawn weed killer?

Herbicides that contain 2,4-D, MCPP, dicamba, sulfentrazone, quinclorac, or triclopyr offer effective control for common lawn weeds. Always read and follow label directions.

How do I get rid of lawn weeds organically?

Top organic options include corn gluten meal for pre-emergence, vinegar formulations, hand weeding, soil solarization, mulching, and improving lawn health and density to outcompete weeds.

Conclusion

Controlling lawn weeds takes diligence and a multifaceted approach. Identifying what weeds are present and their growth habits is the first step toward an effective management plan. Combining cultural practices to promote vigorous grass growth along with targeted mechanical and chemical controls will keep your lawn lush, green and weed-free. Paying close attention and taking action at the first signs of weed emergence will prevent them from spreading and becoming established. With quick identification and control methods like those covered here, you can gain the upper hand over lawn weeds.