9 Grass Weeds With Yellow Flowers

Ever had to deal with weeds in your garden or lawn grass? Well, weeds can ruin a healthy garden or lawn grass and deplete the desired weeds’ nutrients. However, many grass weeds have flowers when they bloom in spring and summer. These flowers come in different shapes, sizes, and colors.

Grass weeds with yellow flowers are identified as weeds that bloom yellow-colored flowers in spring or summer. These weeds are very attractive to pollinators such as bees and birds. These pollinators help to disperse the weeds’ seeds faster and spread them farther over the garden, causing the grass weeds to invade grass faster.

1. Yellow WoodSorrel

Scientific name: Oxalis stricta

Other names: sourgrass, sheep weed, or pickleweed

Identification: The yellow Woodsorrel has bright green heart-shaped leaves and a clover look-alike weed. It produces small, green seed pods. It blooms yellow five-petaled flowers by mid-spring to fall and grows to an average height of 20 inches when mature.

Prevention; maintaining green and healthy grass, mulching the lawn to prevent sunlight from getting to any seeds to prevent germinating.

Control; hand pulling, using Glyphosate to kill the weeds, using pre-emergent and post-emergent herbicides, etc.

Yellow WoodSorrel

Yellow Wood sorrel is one of the major grass weeds with yellow flowers. The bright yellow flowers bloom from mid-spring to autumn and account for the success of yellow woodsorrel in invading gardens as the bright yellow petal attracts insects and birds serve as pollinators. They transfer the seeds of the weed far and wide, and they will germinate if the grass is in full sunlight and fertile.

Yellow Wood sorrel can be prevented by keeping your grass lush and healthy to compete with the weed, mulching the grass to suffocate the seeds, and depriving them of sunlight. However, these methods are not always effective. Yellow woodsorrel can be controlled by hand pulling in the early stages, glyphosate chemicals, post-emergent herbicides for already germinated weeds, and pre-emergent herbicides after the blooming season.

2. Birdsfoot Trefoil

Scientific name: Lotus corniculatus

Other names: Upright trefoil, eggs and bacon, birdsfoot deervetch, common trefoil, and common bird’s foot.

Identification: The Birdsfoot Trefoil weed grows to about 25 to 35 inches in height, erect or prostrate and gets the name ‘bird’s foot due to the appearance of the seed pods on its stalk. The clover look-alike produces pale yellow to bright yellow fragrant flowers tinged with red, earning it the “eggs and bacon” reference.

Prevention: Applying nitrogen-containing fertilizers can prevent birdsfoot trefoil from germinating in the grass.

Control: Hand pulling, shading young seedlings to kill them, use of broadleaf herbicides

Birdsfoot Trefoil

Birdsfoot Trefoil is one of the major grass weeds with yellow flowers. The weed is commonly grown from livestock food (fodder), to prevent erosion, and for revegetation in wildlife habitats. However, birdsfoot trefoil is a very invasive weed and once established in an area, can outcompete native species by spreading quickly. The weed can survive in acidic soils with drought and compete with unhealthy grass.

Birdsfoot trefoil can be prevented by regularly applying nitrogen-containing fertilizers to keep the grass healthy. However, once this weed is established, it spreads fairly quickly. Birdsfoot trefoils can be controlled by hand pulling in the early stages of invasion. Broadleaf herbicides can be used to kill these weeds efficiently.

3. Black-Eyed Susans

Scientific name: Rudbeckia hirta

Other names: Brown-eyed Susan, Brown Betty, Gloriosa Daisy, golden Jerusalem, English bull’s eye, poor-land Daisy, and yellow ox-eye Daisy.

Identification: Black-eyed Susans resemble daisies with long, thin, and dark green stalks that grow to about 20 inches. The leaves are in alternate arrangements with large yellow flowers. The flower has a brown center with clusters of seeds to be dispersed.

Prevention: keep the grass healthy with good drainage.

Control: hand pulling before the seed forms, applying herbicides to recently cut black-eyed Susans to prevent reoccurrence.

Black-Eyed Susans

Black-Eyed Susans are one of the major grass weeds with yellow flowers. The weed is often considered a wildflower although they usually grow in places they were not planned as are often regarded as weeds. Black-eyed Susans are prized in some states due to their beautiful flowers.

Black-eyed Susans are drought-resistant and grow well when in dry and hot weather. The seeds are easily dispersed and can invade your grass if not controlled and compete with the desired grass. Making sure the grass is healthy and water in hot weather can prevent Black-Eyed Susans, hand-pulling and herbicides are effective methods of control.

4. Purslane

Scientific name: Portulaca oleracea

Other names: Little Hogweed, Pursley

Identification: Purslane grows as a mat in grass extending low and wide. It has multiple stems with oval leaves with a red-purple tint. The weed produces small yellow flowers on hot sunny days in the summer.

Prevention: Apply pre-emergent herbicide before the growing season.

Control: Hand-pulling when still young or with the use of herbicides.


Purslane is one of the major grass weeds with yellow flowers. The succulent weed is well-known for its versatility. Purslane is an edible weed and can be consumed raw by humans. It is often used in salads and has a slightly sour taste. It is also eaten by grazing animals.

Purslane stores water in its leaves allowing it to survive droughts. They also propagate via the root, leaf, and seed making the weed very difficult to get rid of as any part left behind can regrow. Applying pre-emergent herbicides before growing seasons can prevent purslane from germinating. Hand pulling of these weeds should be thorough as any part of the plant can propagate. Herbicides are also effective for control.

5. Black Medic

Scientific name: Medicago lupulina

Other names: Black Medick, Nonesuch, Hop Clover

Identification: Black medics closely resemble the clover plant with its three leaves. However, black medic leaves are hairy with teeth marks towards the top and a yellow flower at the center. Young black medic often grows vertically, but mature black medic weed can grow to 6 to 30 inches erect.

Prevention: Applying nitrogen-containing fertilizers

Control: Hand pulling, use of broadleaf herbicides.

Black Medic

Black Medic is one of the major grass weeds with yellow flowers. Black medics thrive in almost every condition from dry to well-drained soils, and alkaline to acidic soils. They are also resistant to cold weather and can grow in high altitudes. However, black medics love soils with low nitrogen.

Gardeners can prevent black medic weeds from growing in their grass by applying nitrogen-containing fertilizers to increase the nitrogen content of the soil. If the weed is in its early stages of invasion, hand pulling can be an effective control method. If it has passed this state, broadleaf herbicides can be used to kill black medic weeds.

6. Golden Clover

Scientific name: Trifolium aureum

Other names: Large hop trefoil, large hop clover, Palmate Hop Clover

Identification: Golden clovers are erect weeds growing 3 to 10 inches tall. They have three leaves like the garden clover with bright yellow flowers. The flowers are in small, round, and long arrangements and are located at the end of the stem.

Prevention: Fertilize your grass to keep it healthy enough to compete with any germinating seeds.

Control: Hand pulling, mulching

Golden Clover

Golden Clover is one of the major grass weeds with yellow flowers. Often mistaken for other clover look-alikes, the golden clover has three sessile leaves in a similar shape with a yellow flower at the end of the stem. Golden clovers usually grow in unhealthy grasses and can be prevented by fertilizing the grass to keep it healthy.

When golden clovers have invaded a garden, simply hand-pulling the weeds completely is an effective method of control. Mulching (covering the topsoil) can also be used to suffocate any germinating seeds. Under extreme cases, a broadleaf herbicide can be used.

7. Creeping Buttercup

Scientific name: Ranunculus repens

Other names: creeping crowfoot, restharrow, sitfast

Identification: creeping buttercups have creeping stems with erect flowering stems. The weed usually grows to about 20 inches in height and has white leaves spotted with dark green. They have bright and glossy yellow flowers with five petals and a finely grooved stem.

Prevention: keep the grass healthy and have good water drainage.

Control: Hand pulling for early stages and broadleaf herbicides for late stages.

Creeping Buttercup

Creeping Buttercup is one of the major grass weeds with yellow flowers. The weed is a member of the buttercup family and is usually found in open fields with wet grasses. The creeping buttercup has bright and glossy yellow flowers that help to regulate the temperature of the flowers’ sex organs and also attract insects that serve as pollinators and dispersal methods.

Creeping buttercups love wet soil and are often seen in flooded areas. Maintaining good drainage is a good way of preventing this weed from invading grass. The weed is poisonous and skin contact with the plant sap can irritate it. Hand pulling for early stages and broadleaf herbicides for late stages are good methods of control.

8. Creeping Cinquefoil

Scientific name: Potentilla reptans

Other names: European cinquefoil or creeping tormentil

Identification: creeping cinquefoils have creeping stems that can grow roots, with their leaves with rough edges on upright stalks. The weed produces yellow flowers with five petals when in bloom.

Prevention: keep the grass healthy and well-maintained

Control: hand pulling, repeated treatments of glyphosate herbicides.

Creeping Cinquefoil is one of the major grass weeds with yellow flowers. They are very invasive weeds and if not controlled early and effectively can spread fast across the grass. Creeping cinquefoils are creeping weeds but their leaves and flowers are on upright stalks. They produce yellow flowers with five petals when blooming from May to October.

The creeping cinquefoil weed can be prevented by constant raking while maintaining the surrounding grass. This weakens any sprouting weeds and loosens the tap roots making it easier to hand pull. If the weed has invaded the grass extensively, repeated treatment using glyphosate is an effective means of control.

9. Dandelions

Scientific name: Taraxacum officinale

Other names: Common dandelion

Identification: Dandelions are upright weeds that can grow to about 20 inches in height on maturity. The stems sometimes have a purple tint and are usually covered in hair. Each stem has large, dark green leaves and produces one yellow flower head.

Prevention: have thick healthy grass

Control: use of broadleaf herbicides


Dandelions are one of the major grass weeds with yellow. This is one of the most popular weeds in North America and is often regarded as a wildflower by many. The dandelion produces yellow flower heads that turn into round balls of many silver-tufted fruits that disperse in the wind.

Dandelions can be prevented by having thick healthy grass that can out-compete with the dandelion seeds. Once dandelions have invaded a garden, they are hard to control due to their deep tap roots that grow back after hand pulling. Using a broadleaf herbicide is an effective way to control herbicides. Some home recipes can help kill dandelions.

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