7 Plants That Look Like Clovers and How to Control Them

Spotting a patch of three-leafed weeds in your turf often triggers an immediate reach for a clover-specific herbicide. However, misidentification is one of the most common reasons for failed weed control programs. Several aggressive broadleaf weeds mimic the trifoliate (three-leaf) structure of true clover, but they belong to entirely different botanical families. Applying a standard Trifolium-targeted treatment to these imposters often results in poor efficacy, wasted chemical costs, and unnecessary environmental exposure.

Accurate identification requires examining leaflet shape, flower structure, and growth habits. Below is a comprehensive guide to identifying the most common plants that look like clovers, paired with precise chemical and cultural control protocols to eradicate them from cool- and warm-season lawns.

The Botanical Baseline: True Clover vs. Imposters

True clovers belong to the genus Trifolium (most commonly white clover, Trifolium repens). You can definitively identify true clover by three key morphological traits:

• Leaflet Shape: Oval or teardrop-shaped leaflets with smooth edges.
• The Watermark: A distinct, pale green or white V-shaped chevron (watermark) on the center of each leaflet.
• Flower Structure: Dense, spherical clusters of tiny white or pinkish flowers.

If the weed in your lawn lacks the V-shaped watermark, features heart-shaped or asymmetrical leaves, or produces yellow flowers, you are likely dealing with a clover imposter.

4 Common Plants That Look Like Clovers

1. Oxalis (Woodsorrel)

Oxalis stricta (yellow woodsorrel) is the most frequent culprit in clover misidentification. Unlike the oval leaves of true clover, Oxalis features distinctly heart-shaped leaflets that fold downward at night or during heat stress. It produces small, five-petaled yellow flowers and upright seed capsules that explode when mature, propelling seeds up to 10 feet across the lawn.

Control Protocol: Oxalis is notoriously resistant to standard 2,4-D formulations. Effective post-emergent control requires products containing Fluroxypyr or Triclopyr. For cool-season grasses, a three-way mix of Triclopyr, Fluroxypyr, and 2,4-D (such as Battleship III) applied at 2.2 pints per acre provides excellent curative control. Expect to make a second application 21 days later to catch germinating seeds from the exploded pods.

2. Black Medic (Medicago lupulina)

Black medic shares a family with true clover (Fabaceae) but exhibits different growth patterns. Its leaflets are teardrop-shaped, but the critical identifying feature is the mucronate tip—a tiny bristle or extension of the central vein that protrudes past the end of the leaflet. It produces small yellow flower heads that mature into tight, black, kidney-shaped seed pods, giving the weed its name.

Control Protocol: Black medic thrives in compacted, low-nitrogen soils. Chemically, it is highly susceptible to MCPP (Mecoprop-p) combined with Dicamba and 2,4-D. Products like SpeedZone (carfentrazone-ethyl + 2,4-D + MCPP + dicamba) offer rapid burn-down, often showing necrosis on the weed within 24 to 48 hours. Apply when daytime temperatures are between 65°F and 85°F to prevent turf phytotoxicity.

3. Lespedeza (Japanese Clover)

Lespedeza (Lespedeza cuneata) forms dense, prostrate mats that can choke out thin turf. While it has three leaflets, they are significantly smaller and narrower than true clover, and the stems become highly woody and fibrous at the base by late summer. It produces inconspicuous pinkish-purple flowers in the leaf axils.

Control Protocol: Because of its woody base, Lespedeza is difficult to pull manually. Post-emergent control is best achieved with Triclopyr or Quinclorac. According to NC State TurfFiles, a single application of Quinclorac (Drive XLR8) at 0.367 fluid ounces per 1,000 square feet, combined with a methylated seed oil (MSO) surfactant, provides superior control in bermudagrass and zoysiagrass lawns.

4. Birdsfoot Trefoil (Lotus corniculatus)

Though it sometimes appears to have three leaflets, Birdsfoot Trefoil actually has five: three at the tip of the petiole and two smaller ones at the base. It produces bright yellow and orange flowers that resemble a bird's foot. It is highly drought-tolerant and frequently invades under-fertilized, sandy soils.

Control Protocol: Standard broadleaf herbicides often fail against mature Trefoil. The most effective active ingredient is Metsulfuron-methyl (found in products like Manor or MSM Turf). Because Metsulfuron is a sulfonylurea herbicide, it requires a non-ionic surfactant (NIS) at 0.25% v/v to penetrate the waxy leaf cuticle. Note that Metsulfuron has a long soil residual and should not be used near the root zones of desirable ornamental trees.

Targeted Herbicide Matrix for Clover Imposters

Selecting the correct active ingredient is critical. The UC Statewide IPM Program emphasizes that matching the herbicide to the specific weed species prevents chemical resistance. Use the matrix below to select your treatment:

Cultural Controls: Fixing the Soil Issues That Invite Imposters

Chemical control is only a temporary fix if the underlying turf conditions favor weed invasion. According to Penn State Extension, plants that look like clovers are heavily correlated with specific soil deficiencies.

• Nitrogen Deficiency: Black medic and Birdsfoot Trefoil are legumes capable of fixing their own atmospheric nitrogen. If your soil test reveals nitrogen levels below 2 lbs per 1,000 sq ft annually, these weeds will outcompete your turfgrass. Apply a slow-release polymer-coated urea (like Polyon) at 1.0 lb N/1000 sq ft in early fall to thicken the turf canopy.
• Soil Compaction: Lespedeza and Oxalis thrive in heavily compacted soils where turfgrass roots cannot penetrate. If a screwdriver cannot be easily pushed 4 inches into the soil, core aeration is mandatory. Use a hollow-tine aerator to pull 3-inch cores, leaving them on the surface to break down and reintroduce soil microbes.
• pH Imbalance: True clover tolerates acidic soils, but Black Medic prefers alkaline conditions (pH above 7.0). If your soil pH exceeds 7.2, apply elemental sulfur at a rate of 1.5 lbs per 1,000 sq ft to gradually lower the pH to the optimal 6.2–6.8 range for most turfgrasses.

Frequently Asked Questions

Can I use pre-emergent herbicides to stop clover lookalikes?

Yes, but timing is critical. Oxalis and Black Medic germinate in early spring when soil temperatures reach 55°F to 60°F. Applying a pre-emergent containing Isoxaben (Gallery) or Prodiamine (Barricade) in late winter, before soil temperatures hit 55°F, will create a chemical barrier that prevents the seeds from establishing. Note that pre-emergents will not kill existing mature plants.

Is Oxalis toxic to pets?

Oxalis contains soluble calcium oxalates. While a small amount ingested by a dog or cat rarely causes severe harm, large quantities can lead to gastrointestinal upset, vomiting, and in rare cases, hypocalcemia. If your pets frequently graze on lawn weeds, prioritize rapid removal of Oxalis using targeted spot-treatments rather than broadcast spraying.

Why did my 2,4-D weed killer fail to kill the yellow-flowered clover?

The yellow-flowered weed was almost certainly Oxalis or Black Medic, not true white clover. Oxalis has a waxy leaf cuticle and a deep taproot that allows it to survive standard 2,4-D applications. Furthermore, Oxalis actively goes dormant during high summer heat; applying herbicides during July or August will result in failure. Always treat Oxalis in the cool, active growth periods of spring or early fall using a Fluroxypyr-based product.