Weed ID Guide

Here at Sunday, we believe the best approach to weed control is growing a dense, healthy lawn. Sometimes, though, weeds will work their way into the grass - that is, after all, what weeds are best at! If they get out of hand, they can cause an uneven - and sometimes, unsightly - lawn. But weeds can also disrupt normal lawn functions like promoting good infiltration during heavy storms, or holding the soil in place.

There are two general types of lawn weeds: grassy (or grass-like weeds) and broadleaf weeds. Within each of these categories are two different life cycles, annuals and perennials - knowing which life cycle your weed falls under can help with control. Mosses and algae may also crop up from time to time. Regardless of the weed type, we recommend an Integrated Pest Management approach to weed control, where you practice identifying weeds and improving lawn habitat, before reaching for Sunday weed control products or harmful chemicals.

How to approach a weed issue

Prevention. Prevent weeds from occurring through proper lawn management – no need to control if they never pop up! 

Detection. If they do creep in, spend some time finding the different plants in the lawn – this is a great activity to do with the kids! Diversity is cool!

Know where they are. Determine what kind of habitat weeds are living in. 

Are weeds in areas where the lawn is thin? Wet? Compacted? Shady?

Correct ID. Identify weeds so you know what you’re up against.

Monitor. Track weed activity and treatment.

  1. Control first by hand-weeding and adjustments to lawn management; only rely on chemicals as a last-resort.
  2. Monitor the areas where you are weeding and track changes (weed presence) over time. 

Most Common Weeds in Lawns

Need help identifying your weeds? Below are the most common weeds in Sunday customers’ lawns and info on how you can manage them before reaching for weed control products.

Grass and Grass-Like Weeds

Crabgrass (Digitaria spp.)

Type of Weed: Annual grass.

Growth Habit: Prostrate growth. Crabgrass can root at the nodes and spread by seed. Tends to come up early and dies off at first frost, leaving bare spots in winter and spring.

Where you’ll find it in your yard: Generally found in places that are hard to grow healthy (desired) grass like disturbed soils and areas along sidewalks; however, crabgrass is adapted to a wide range of growing conditions, and is common is lawns that are mowed too short or that have bare patches.

Quick ID: Leaf blade is flat and yellow-green, but older leaves may turn reddish or purple. Flower heads have finger-like spikelets and also may turn reddish or purple as they age. 

Natural Weed Prevention and Reduction Practices

  1. Raise your mowing height a bit to allow your turf to shade out the crabgrass. 
  2. Seed any bare patches to prevent crabgrass germination. 

Sunday Funday Facts: We’ve got a double whammy for crabgrass! Our first fun fact:  the flowers look like the five digits (fingers) on your hand – it’s latin name is digitaria for this reason! Second, crabgrass actually has the same life cycle as corn. It comes up in the beginning of the season when it’s moist, but when it’s hot and dry, it thrives – just like corn in the late summer!   

Sunday Product Suggestion:Weed Warrior

 

Annual bluegrass (Poa annua)

Type of Weed: Grass. Annual bluegrass can actually be annual or perennial (confusing, we know!), but MOST of the time will be an annual in the average lawn.

Growth Habit: Tufts of grass, extremely shallow rooted – live fast, die hard approach to growing where the plant isn’t invested in growing long-term.

Where you’ll find it in your yard:  Adapted to a broad range of growing conditions, but mainly found in wet, disturbed (high traffic or pet waste) areas of over-fertilized lawns. 

Quick ID: Most of the time people notice it in flower – usually the only grassy plant flowering in a regularly mowed lawn. It’s also the first grass to green up in the spring because it’s a winter annual that germinates from fall seed. Other ways to recognize: 

  1. Mainly lighter, brighter green than most lawn turf
  2. Boat-shaped leaf tip
  3. Seed heads are fuzzy panicles and whitish or very light green in color

Natural Weed Prevention and Reduction Practices: Annual bluegrass is one of the toughest weeds to control. Because it is a turfgrass, it likes what your turf likes. If you do see some annual bluegrass pop up, make sure to do the following: 

  1. Mow at the proper height for your grass
  2. Audit and check your irrigation system to determine if you are over or under watering
  3. Remove annual bluegrass flowers. Then, dispose or compost. 

Sunday ProTip: When removing annual bluegrass flowers, you are usually instructed to dispose of the flowering heads. Try to limit this method to localized areas of the lawn where the infestation is very dense. Why? Since you are disposing of these grass clippings, you will also be removing critical nutrients from your soil (learn more about grasscycling).  

Sunday Product Suggestion: Weed Warrior

 

Goosegrass (Eleusine indica)

Type of Weed: Summer annual grass.

Growth Habit: Clumped, bunch-type grass.

Where you’ll find it in your yard: Goosegrass prefers warmer temperatures than crabgrass and needs moist soil to establish. It also does well in compacted, low quality, under-fertilized soil.

Quick ID: Characterized by zipper-like seed head with small black seeds. Can look similar to crabgrass, but goosegrass is usually white or silver in the center of the plant.

Natural Weed Prevention and Reduction Practices: Goosegrass is another weed that thrives in moist soil. Here’s some ways to remove without chemicals: 

  • Try cutting back on irrigation after hand-weeding (or digging up) goosegrass clumps. 
  • The best way to avoid an infestation is to utilize resilient grass seed blends to fill in bare patches so annual weeds can’t move into bare soil. 

Sunday ProTip: If you have a large population of well-established goosegrass in your lawn, the best thing you can do is wait until it gets cooler and fix those areas of the lawn with Sunday Grass Seed to make those areas more competitive to weeds. 

Sunday Product Suggestion: Currently, no Sunday products are available to control this weed. We recommend physical removal and preventative measures when possible.

 

Dallisgrass (Paspalum dilatatum)

Type of Weed: Perennial grass.

Growth Habit: Clumpy, but can produce short, thick rhizomes.

Where you’ll find it in your yard:  Typically found in areas where grass is not well maintained and in trouble. 

Quick ID: Very coarse (broad) leaves, compared to most turfgrasses. Seedheads have tiny black flowers. 

Natural Weed Prevention and Reduction Practices: If you do get a heavy Dallisgrass infestation, the best way to deal with it is: 

  1. Dig up the clumps with a shovel
  2. Reseed the area to ensure you get some healthy turf coverage back. 
  3. Treat similarly to crabgrass (even though a perennial) – raise your mowing height and crowd this weed out!

Sunday Product Suggestion: : Currently, no Sunday products are available to control this weed. We recommend physical removal and preventative measures when possible.

 

Sedges (Most Common: Yellow Nutsedge, Purple Nutsedge, Kyllinga) (Cyperus and Kyllinga spp.)

Type of Weed: Perennial grass-like (but not actually a grass!).

Growth Habit: Upright; spreads by rhizomes, seed, and nutlets (tubers). 

Where you’ll find it in your yard: Common in wet areas and may also show up where soil was transplanted into the lawn (topsoil, adding nursery plants to the landscape).

Quick ID: Sedges closely resemble grasses, but a key identification feature is their triangular stems and underground nutlets! 

Natural Weed Prevention and Reduction Practices: 

  1. Sedges love soggy soil – reduce irrigation to dry out the soil. 
  2. When hand-weeding, make sure you remove the nutlets from the soil, or they’ll grow back! 

Sunday ProTip: Need help determining if you have a sedge or a grass? Look at the stem! Sedges have edges, rushes are round, and grasses are hollow – what have you found? 

Sunday Product Suggestion: Currently, no Sunday Products are available to control this weed. We recommend physical removal and preventative measures when possible.

Broadleaf Weeds

Dandelion (Taraxacum officinale)

Type of Weed: Perennial broadleaf.

Growth Habit: Clumped, with a very deep taproot.

Where you’ll find it in your yard: Adapted to a broad range of growing conditions, but commonly associated with high K and Ca soils.

Quick ID: Long, broad, slightly to deeply lobed leaves. Each plant has a single yellow flower which turns into a white puff-ball of seeds. 

Sunday Funday Fact: Dandelion is named for the teeth of the lion, because it’s leaf margins are so jagged. 

Natural Weed Prevention and Reduction Practices: Dandelions can be tough to deal with. Here’s our best tips: 

  1. New plants can grow from the deep taproot, so it’s always best to hand-weed dandelions when they are smaller in size and when soils are slightly wet to allow better extraction of the long root!

Sunday ProTip: If you can, leave your dandelions for the pollinators! These sunny weeds are one of the earliest sources of pollen for insects when they first emerge in the spring. Leave the flower until it begins to set seed and then cut the flowering head off and spot treat with Sunday Weed Products.  

Sunday Product Suggestion: Dandelion Doom and Weed Warrior

 

Prostrate knotweed (Polygonum aviculare)

Type of Weed: Summer annual broadleaf (same family of plants as Rhubarb and Buckwheat!).

Growth Habit: Prostrate. 

Where you’ll find it in your yard: Adapted to a broad range of growing conditions, but commonly found in compacted soils and high traffic areas near driveways and sidewalks. Usually one of the first weeds to come up in the spring!

Quick ID: Blue-green alternate leaves. An ocrea (membranous sheath) surrounds the stem at the base of the leaf, and radiating stems have many swollen nodes. Flowers are small and white. Prostrate knotweed has a long, thin taproot.  

Natural Weed Prevention and Reduction Practices: 

  1. Knotweed loves compacted soils, so consider aerating soil. 
  2. You can also try to reduce traffic in knotweed-prone areas, where the soil can’t maintain grass growth. 
  3. Hand-pull knotweed before it seeds, and patch any bare spots with turf seed.

Sunday ProTip: This weed is critical to take care of – because it is a summer annual, it will die off early in the season, leaving behind a bare spot in the soil open for new weeds to move in. 

Sunday Product Suggestion: Dandelion Doom*

 

White Clover (Trifolium repens)

Type of Weed: Perennial broadleaf legume.

Growth Habit: Low growing, creeping, growth; can root at nodes. 

Where you’ll find it in your yard: Adapted to a broad range of growing conditions.

Quick ID: Three rounded leaves – also known as trifoliate leaves (unless you’re lucky and find a four-leaf!); often, leaves will have white “watermarks” known as white corona. Flowers are sphere-shaped and white, often with a pink base.

Natural Weed Prevention and Reduction Practices:  

  1. Hand-weed clover
  2. Mow off flowers before they seed (this is best done in the early morning to avoid harming pollinators!)
  3. Clovers thrive in low-nitrogen, high-phosphorus soils, so adjust fertilization based on soil tests!
  4. If you let it grow tall, this plant doesn’t tolerate drastic cutting (the one time it’s a good idea to violate the ⅓ rule!). 

Sunday ProTip: Clover is great for the bees, but it can actually be good for the lawn too! Clover is a legume and a nitrogen-fixer so you might notice the grass near the clover is darker. Bonus? High populations of clover can also help eliminate crabgrass problems in the lawn. Win-win.

Sunday Product Suggestion: Dandelion Doom or Weed Warrior*

 

Creeping Charlie (Ground Ivy) (Glechoma hederacea)

Type of Weed: Perennial broadleaf.

Growth Habit: Creeping (not necessarily prostrate, though). Can root at nodes and spread by seed. 

Where you’ll find it in your yard: Creeps out of flower beds and landscaped areas (looking for full sun), and typically found in lawns allowed to grow too tall and then cut too low (e.g. not following the ⅓ rule!). Once it invades, it can be very difficult to remove. 

Quick ID: Creeping Charlie is in the mint family, so it has a four-sided (square), hairy stem, and a distinct minT scent when crushed. Leaves are kidney-shaped or rounded with scalloped edges. Flowers are purple with red speckles.

Natural Weed Prevention and Reduction Practices: Creeping Charlie likes shade, and will invade shade-stressed areas, so make sure you’re planting the right grass in the right place

Sunday ProTip: Mule Team borax applied at full bloom or after the first frost can provide some control of creeping charlie. 

To treat 1,000 sq. feet:

  1. 10 oz. Twenty Mule Team Borax
  2. dissolve in 4 oz. warm water
  3. then dilute in 2.5 gal. water

Sunday Funday Fact: Creeping Charlie is also known as Gill on the Ground and in parts of the midwest it’s used to make beer! 

Sunday Product Suggestion: Dandelion Doom*

 

Henbit (Lamium amplexicaule)

Type of Weed: Winter annual broadleaf.

Growth Habit: Prostrate.

Where you’ll find it in your yard: Prefers moist to wet soils. 

Quick ID: Greenish purple four-sided stems with egg-shaped, toothed leaves. Flowers are reddish-purple and look like tiny orchid flowers with dark red spots. 

Natural Weed Prevention and Reduction Practices:

  1. Hand-weeding and proper irrigation should help control henbit. 
  2. The best time to manage any type of winter annual is in the fall when they first emerge – if you see in the spring it’s too late to manage. But don’t worry! By that point, they’re going to die-off anyways when temperatures warm up. 

Sunday ProTip: Henbit and purple deadnettle look very similar (they’re closely related!) but purple deadnettle’s upper leaves have petioles (tiny stems) and are usually purple-tinted, while henbit’s upper leaves are attached directly to the stem. 

Sunday Fun Fact: Hens aren’t the only creatures to like this little plant! Henbit is very popular with and great for pollinators too! 

Sunday Product Suggestion:Currently, no Sunday products are available to control this weed. We recommend physical removal and preventative measures when possible.

 

Common Chickweed (Stellaria media)

Type of Weed: Summer or winter annual broadleaf.

Growth Habit: Creeping – so much so that it tends to creep into sidewalks, flower beds and can even grow right on top of the grass on your lawn. 

Where you’ll find it in your yard: Prefers cool, moist to wet conditions and compacted soils.

Quick ID: Small, oblong, pale green leaves with hairy stems; white star-like flowers. 

Sunday Funday Fact: Chickweed is a member of the Pink family and has the characteristic swollen nodes and opposite leaves.  

Natural Weed Prevention and Reduction Practices

  1. Since chickweed prefers moist soil, try adjusting how you water your lawn! Deep, infrequent irrigation can help fight water-loving weeds like chickweed.  

Sunday ProTip: There’s actually another type of chickweed – called Mous-ear Chickweed. This is a perennial weed that is found in lawns that are in bad shape, and may signify you have an under-fertilized, improperly watered lawn. 

Sunday Product Suggestion:Dandelion Doom* or Weed Warrior

 

Field Bindweed (Convolvulus arvensis)

Type of Weed: Perennial broadleaf (in the morning glory family!) 

Growth Habit: Trailing vine, which grows stronger if lawns are drought-stressed and poorly fertilized. Generally a sign that a lawn is in trouble. 

Where you’ll find it in your yard: Adapted to a broad range of growing conditions, but common in dry soils. One of the most difficult to control perennial weeds – while you can eliminate weeds at the surface, it has an extensive underground root system (up to 8-9 feet deep!).

Quick ID: Triangular or arrow-shaped leaves; flowers are white to pale pink and look like mini morning glory or petunia flowers.

Natural Weed Prevention and Reduction Practices

  1. Bindweed reproduces by seed and broken root fragments – so make sure you remove underground stems when you hand-weed! 
  2. Remove vines as soon as you see them, and monitor regularly. 
  3. Irrigate properly. This weed also likes dry soils, so make sure you are irrigating enough to keep your turf healthy! 

Sunday ProTip: Bindweed is more noticeable in summer months during dry conditions when mowing is skipped and it’s able to flower in the lawn. It cannot tolerate frequent mowings – when it gets taller you can then mow to reduce its growth and spread. 

Sunday Product Suggestion: Currently, no Sunday products are available to control this weed. We recommend physical removal and preventative measures when possible.

 

Black Medic (Medicago lupulina)

Type of Weed: Annual broadleaf legume (which means it can fix its own nitrogen!). 

Growth Habit: Taproot, with spreading, prostrate growth.

Where you’ll find it in your yard: Adapted to a broad range of growing conditions. Often appears in summer, in areas of lawn where grass isn’t actively growing and soil cannot hold water due to dry conditions. 

Quick ID: Three rounded leaflets; flowers are small, yellow and bunched; seed pods are black grape-like clusters. 

Natural Weed Prevention and Reduction Practices

  • Hand-weeding trouble spots is usually effective. 
  • Black medic is a prolific seed producer – try to remove plants (especially flowers) before they seed. 

Sunday ProTip: Lookalike alert! Black medic and clover look very similar when they aren’t flowering – so how can you tell them apart? 

  • White clover leaflets are all equidistant from the main stem, while the petiole (small leaf stem) of the central leaflet on black medic is slightly longer than the two on either side. 
  • Plus, black medic has a distinct “spur” at the tip of each leaflet. Yee-haw! (Or should we say “bee-haw!” since black medic is highly attractive to bees and other pollinators!) 

Sunday Product Suggestion: Dandelion Doom**

 

Woodsorrel (Oxalis stricta)

Type of Weed: Broadleaf that can be a summer annual in the north or a perennial in the south.

Growth Habit: Similar growth habit to clover. Reproduces by seed, germinates from spring-summer, and has very shallow roots. 

Where you’ll find it in your yard: Adapted to a broad range of growing conditions but typically invades areas that get very wet or very dry (areas where water might collect, but over time areas that also can’t maintain water).  

Quick ID: Hairy stems with distinct 3-heart-shaped leaflets per leaf. Leaflets may fold in half in the heat or at night. Flowers are 5-petaled and yellow.

Natural Weed Prevention and Reduction Practices:  

  1. Woodsorrel is easily removed by hand – so roll up your sleeves, give it a yank, and save the chemicals for when they’re really needed! 

Sunday Funday Fact: Woodsorrel is a flowering plant that produces a dehiscent seed that opens with ripe – woodsorrel seed pods split from pressure and spread seed through this ballistochory movement. 

Sunday Product Suggestion: Dandelion Doom

Moss and Algae

Type of Weed: Moss – these are not like any other plant on this list because they are non-vascular. These are more like fungi than other plants. 

Growth Habit: Low-growing.

Where you’ll find it in your yard: Damp or wet shady areas and in bare soil between grass plants.

Quick ID: Very small black, green, or yellow-green leaves with a spong-like or slimy texture. 

Natural Weed Prevention and Reduction Practices

  1. Moss and algae are common in wet, shady areas with thin turf – so, reduce irrigation and seed bare, shaded areas with a shade-tolerant turf. 
  2. If you have dry areas with moss, here’s why: at some point this area had too much water. Sometimes moss persists due to age and longevity of growth. This type of moss will need to be removed physically (or with Sunday Dandelion Doom). 

Sunday ProTip: Large populations of moss within your lawn is an indicator that this isn’t the best place for grass. This area would be perfect for a rock garden, patio, or another use. Bonus Tip: if you remove the moss, place in a blender with buttermilk and then pour over your new rock garden – the moss will re-establish itself. 

Sunday Product Suggestion: Dandelion Doom* or Weed Warrior

*Not currently registered for this weed in California 

**Approved for suppression of this weed in California

Cited Sources

Iowa State Extension. Borax on Ground Ivy: Boon or Bane?

OARDC Weed Lab. Weed Identification | OWL. The Ohio State University. 

Patton, A. et al. Turfgrass Weed Control for Professionals. Purdue University Extension.

Turgeon, A.J. Turf Weeds and Their Control

University of Minnesota. Is this plant a weed?