Plant identification is something even the most experienced gardeners often struggle with. This is especially true when it comes down to distinguishing very similar plant species from each other. So if you’ve ever thought that all grassy weeds look more or less the same, you’re certainly not alone.
By the way, identifying weeds isn’t just about expanding your botanical knowledge. In order to effectively kill and prevent many grassy weeds, you need to know exactly which variety you’re dealing with. The information I’ve provided below will help you identify common weeds that look like wheat and control their presence in your lawn or garden.
Identifying Grassy Weeds That Look Like Wheat
One of the most common comparisons I hear from people struggling with grassy weeds is that the flower or seed heads resemble those of wheat. While this description alone won’t narrow down the culprit completely, it can definitely help steer you in the right direction.
Here are 10 of the most common grassy weeds that resemble wheat and how to distinguish them:
Annual ryegrass, sometimes known as Italian ryegrass, is an annual or biennial grass species that is often used in residential lawns. But when this plant grows in areas it’s not desired — including native habitats, crop fields, and non-ryegrass lawns — it is considered a troublesome weed.
Ryegrass is a bunching-type grass. In other words, it grows as individual bunches instead of forming a uniform carpet like other grass varieties.
Left to its own devices, annual ryegrass will grow to 2 or 3 feet tall. It produces wheat-like flower spikes and seed heads throughout spring, summer, and fall.
Barnyard Grass or Junglerice
Barnyard grass is a wild cereal crop native to tropical climates in Asia and Africa. Unfortunately, this grassy weed has become invasive throughout much of Australia, North America, and South America.
It is found in wild environments as well as gardens, lawns, and agricultural fields. You’re most likely to encounter this grassy weed if you live in a temperate or tropical region.
Barnyard grass grows to about 3 feet tall and flowers from mid-summer to early fall. Both the flower stalks and ensuing seed heads could be mistaken for wheat without closer inspection.
Couch grass or Quackgrass
Elytrigia repens goes by many names. While I’ve always known this persistent weed as quackgrass, you may be more familiar with names like couch, quick, or twitch grass.
No matter what you call it, this grassy weed is a commonly spotted nuisance in lawns around the world. Couch grass can grow up to 4 feet tall and, according to the University of Vermont, may be easily mistaken for annual ryegrass when it goes to seed.
One of the reasons couch grass is so pervasive is its creeping growth habit. A single plant can spread rapidly across a lawn via underground stems called rhizomes. Combined with annual seed production, couch grass is capable of reproducing incredibly fast.
Dallisgrass is a South American perennial that readily smothers turf grasses when it invades residential lawns. It’s most invasive in the southern and northwestern parts of the United States.
This grassy weed is most easily identified by the thick, spreading blades that grow in bunches. It reproduces by seed and rhizome, so can take over a property fairly quickly if left untreated.
Dallisgrass grows to about 10 inches tall when not mowed. Despite its resemblance to wheat, dallisgrass bears distinctive tassel-like flowers and seed heads that set it apart from other weedy grasses.
Feather Finger Grass
While feather finger grass is native to much of the world’s temperate regions, it’s also considered a weed in areas. Its hardy nature allows it to outcompete other plants — including turf grasses — quite easily.
Feather finger grass grows in bunches that can reach up to 3 feet tall. Aside from its height, this grassy weed is fairly unassuming until the flower stalks emerge in mid-summer.
The common name for this weed makes sense when you look at the flowers. Each flower head features several hairy tassels that resemble a feather duster from a distance.
Giant foxtail, also known as Japanese bristlegrass, is a common weed in agricultural fields throughout the United States and similar climates. However, it can also invade residential lawns and parks when left unchecked.
As an annual grass, giant foxtail reproduces incredibly fast. All it takes is one summer for a single seed to fully mature and disperse hundreds of its own offspring that will germinate the following year.
Giant foxtail flowers are quite impressive. You can identify this grassy weed by the large, bristle-like flower spikes that can grow up to 7 inches long. Giant foxtail blades can reach up to 5 feet in height.
(Hordeum murinum spp. Leporinum)
Hare barley is a subspecies of wall barley. While these plants are native to Europe and northern Africa, they have naturalized throughout most of the world due to their use as cereal and forage crops.
This annual grass can grow over 3 feet tall. The flower heads closely resemble those of wheat or wild oats but tend to have hairier panicles.
Hare barely typically goes to seed in late spring or early summer. The seeds are incredibly sharp and can cause ulcers in the mouths of grazing animals.
So far, we’ve discussed both foxtails and barleys. Despite the somewhat confusing name, foxtail barley is decidedly an example of the latter.
It may surprise you that foxtail barley is native to North America. Yet it is still considered a weed in the United States because it invades lawns and crop fields, and easily overtakes other native species. According to the University of California, foxtail barley is attracted to moist environments.
Foxtail barley is less of a problem in regions such as the UK, where it is sometimes grown as an ornamental grass.
Rarely exceeding 2 feet in height, you can tell this weed apart from hare barley by the absence of auricles. (An auricle is the shirt collar-looking outgrowth located where a grass blade exits the sheath.)
Johnson grass is a perennial species native to Asia and northern Africa. It stands out from most other grassy weeds due to its height — plants can reach up to 8 feet tall.
Johnson grass exists almost everywhere in the world except for Antarctica. While there are benefits to growing Johnson grass (e.g., erosion control and livestock feed), it’s often labeled a weed due to how easily it outcompetes other plants.
If the sheer height of this grassy weed isn’t enough for a positive ID, keep an eye out for purple flowers that form loose spikes in late summer or fall.
Yellow foxtail is one of the most common grassy weeds I see on my own lawn. This is another foxtail variety native to Europe and Asia but found throughout much of North America and similar climates.
Blades can reach 3 feet in height if not cut. You may notice a red tint at the base of the plant (though some other grassy weeds share this trait as well).
As the name implies, the flowers of yellow foxtail appear gold or yellow at maturity.
How To Get Rid Of Grassy Weeds on Your Lawn
As is the case with almost any weed, grassy weeds are best controlled via herbicide. The unfortunate thing about grassy weeds in particular, though, is that most herbicides that target them will also kill regular turf grass.
Some grassy weeds can be controlled with selective herbicides. This is why identifying the exact weeds plaguing your lawn is so important before deciding on a management strategy. I also recommend knowing which species of turf grass you have to ensure any selective herbicide formula is safe to use.
If you have only a few grassy weeds invading your property, hand-pulling could be an option. You may want to invest in a weeding tool to remove the roots from the soil. Keep in mind that some grassy weeds spread via horizontal stems and are nearly impossible to eradicate without chemical controls.
In cases where selective formulas won’t work and hand-pulling is impractical, you will need to apply a non-selective herbicide or smother the area as a last resort. Non-selective herbicides include chemicals like glyphosate (the main ingredient in Roundup) that target all plants equally. This means that all weeds and turf grass in the treated area will be affected. Once the area is clear of grassy weeds, you can reseed with your desired turf species.
How To Prevent Grassy Weeds
They say prevention is the best medicine. I often find this to be the case when it comes to lawn care. Preventing grassy weeds from taking root in the first place will almost always require less work than treating them after they appear.
My go-to strategy against stubborn grassy weeds is to apply a pre-emergent herbicide at least once per year. Pre-emergent herbicides work by interfering with healthy seed germination so new weeds never have a chance to sprout. The key is to treat your lawn after weed seeds are dispersed but before they start germinating.
However, I do advise against using pre-emergent herbicides if you plan to plant grass seeds anytime in the near future. Many formulas that target grassy weeds also prevent turf grass germination.
Other effective strategies to prevent or minimize grassy weeds include frequent mowing and overseeding.
Mowing often during the spring, summer, and fall will stop many common weeds from going to seed. While this won’t kill the existing weeds it will put a large dent in the next generation.
Meanwhile, repairing thin or bare patches in your lawn by overseeding will eliminate areas where weeds can easily take root.