Grassy weeds are invasive and unhealthy plants that look like regular grass, able to take over your entire lawn easily. Because grassy weeds (sometimes called grass-like weeds or grass weeds) look so similar to standard turfgrass found all over Colorado, they stealthy take over your lawn, stealing nutrients and minerals from healthy grass. At the same time, their roots entrench themselves in the root system of your lawn. These nuisance weeds may be stealthy, but there are still ways we can combat them to keep our lawns at their best.
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Identifying Grassy Weeds In Colorado
While Colorado’s most common grassy weeds can blend with healthy grass, we can still spot the culprits by getting to know their characteristics. By familiarizing yourself with these grassy weeds, you can be on the lookout for these pesky weeds and move quickly against them. The first step is getting familiar with the local grassy weeds most prone to your area. In lower elevations in Colorado, the usual suspects of grassy weeds are crabgrass, foxtail, barnyardgrass, and goosegrass. Though all of these weeds look similar to healthy turfgrass, there are distinct characteristics of each grassy weed species that will help you differentiate turfgrass from grassy weeds. Look for the following when trying to identify grassy weeds in your lawn:
- Taller growth than the surrounding grass
- Quicker growth rate
- Brighter or darker leaf blades
- Different leaf shapes (rolled, pointed, etc.)
- Discolored or thin patches of grass
- Prominent seed heads
- Shallow, invasive roots
- Bunching or clumping growth pattern
Types Of Grassy Weeds
Understanding the different types of grassy weeds in Colorado really just comes down to knowing what each type looks like. Some grassy weeds have deeper roots than others, and some produce seedheads that help spread a grassy weed invasion across your yard. If you know what types of grassy weeds have which characteristics, you will have an easier time trying to prevent or remove them before they can do any serious damage to your turf. The sections below detail some of the most common types of grassy weeds you are likely to encounter in our area.
Crabgrass
Crabgrass is perhaps the most common of all grassy weeds in Colorado to invade your lawn. This master of stealth is often mistaken for other types of healthy grass, such as bromegrass, tall fescue, or orchardgrass. It can also be mistaken as goosegrass in early growth, another invasive weed found in Colorado. Fortunately, the same herbicides needed to combat crabgrass also work on yellow foxtail.
When looking for crabgrass, look for the following characteristics:
- Light apple green sprouts,
- Grows in bunches
- Leaves grow to be long and coarse
Once identified, making a plan to combat this pesky weed is easy. There are a few ways to go about getting rid of crabgrass.
- Weeding: Hand-pulling these individual weed plants by the roots is one of the surest ways to eliminate crabgrass from your lawn. The process can be tiring and time-consuming and must be done regularly to keep crabgrass from spreading. It’s best done in late spring before the crabgrass grows large enough to spread around its seeds.
- Apply Herbicides: Using weed killers to control and stop the spread of crabgrass is one of the most effective ways to control and kill crabgrass on your lawn. Not all herbicides are considered equal, so be sure to consult a lawn care expert on the most effective and safe herbicides to use on your lawn.
Foxtail
Another grassy weed commonly found in Colorado is Foxtail. This nuisance weed is invasive and can take over your lawn quickly but it can also be dangerous. Mature yellow foxtails are incredibly dangerous to animals, especially cats, and dogs. The mature seed’s spiked front and barbed ends can easily get lodged into your pet’s paws or skin, and it’s small enough not to be noticeable immediately. They burrow into the animal’s skin, causing severe injury, infection, and sometimes even death.
These factors above give a sense of urgency to get control of these weeds and remove them as quickly and efficiently as possible. Yellow foxtail has distinct characteristics that make it easy enough to spot.
- Seedlings have elongated leaf shapes and are light green in color.
- Grow in close clusters
- Long, silky hairs on the leaf blade
- Cylindrical seedhead with spiky hairs. Yellow when mature
- Mature blades are flat, 10-12 inches long
While not as harmful as yellow foxtail, green foxtail is another type of foxtail that can invade your lawn and quickly take over. While similar in appearance, you can identify a green foxtail by the distinct differences from yellow foxtail.
- Smooth oval leaves with no hair
- Flat stem with hairy margins
- Upright, cylindrical seed head, light green soft spikes
If the seed head is upright and light green, you can easily assume it’s a green foxtail weed. Because of its long, fibrous roots, hand pulling is not recommended for removing foxtail. Fortunately, there are herbicides available in home improvement stores and gardening centers that can get rid of foxtails without harming any healthy grass or plants.
Barnyardgrass
Another rather unattractive weed that can find a home on your lawn in Colorado is Barnyardgrass. It usually makes its presence known in the summer when it matures from small leaves that blend effortlessly with turf grass into taller stalks. This weed spreads through seeds, eating up all the nutrients and minerals meant for healthy turf grass, with its roots growing deep into the soil.
Thankfully, this troublesome weed is easily identified with its unique characteristics.
- Thick stems with maroon tint at the base.
- Flat and smooth leaves
- Faint white vein in the center of leaves
- Spiky seedheads can be 4-8 inches long with a green, red, or dark purple tint.
- Thin, long branching root system
- Mature weeds can grow up to 5 feet tall
While barnyardgrass may be easy to identify, they are notoriously difficult to eliminate. Hand-pulling the weeds is an almost guaranteed waste of time due to the high chance of the fragile roots breaking off. Herbicides are the best choice to get rid of barnyardgrass.
Goosegrass
Goosegrass is a pesky weed and master of disguise. Not only does it blend with turf grass easily when sprouting, but it’s also often mistaken for crabgrass. Like all grassy weeds, goosegrass spreads with seeding, though they germinate in winter rather than spring. Goosegrass loves full sun and compacted soil, so much that when trying to identify the weed, goosegrass is almost always the culprit in a sunny area of compacted soil.
When identifying goosegrass, these are the key features to look out for.
- Grassy green-colored leaves with a thick texture.
- Grows from a cluster and branches out in a wagon wheel-like shape
- Large and hairy seeds, compared to crabgrass
- Stems are flat and green, pale green, and occasionally silverish hue.
- Light green colored flower
Fun Fact: Goosegrass is also edible, being part of the Poaceae family. It’s nicknamed “famine grass,” though it is a lot of work to harvest.
Because Goosegrass grows in compacted soil, it’s tough to get rid of them by hand-pulling. While you can mow them to keep them from spreading seeds, this doesn’t necessarily get rid of them long-term. Thankfully, goosegrass is an annual eliminated by frost, so waiting until the cold autumn and winter months will effectively eliminate it. Herbicides are also an option, though this hearty grassy weed may need the expertise of a lawn expert to remove it effectively and safely without affecting nearby healthy plants.
Life Cycle Of Grassy Weeds
Annual grassy weeds are plants that complete their life cycle within one year. They tend to have a short germination period and can quickly invade a lawn, growing rapidly in the warm months before dying off in winter. Most annual grassy weeds produce seeds that are dispersed every season and remain dormant in the soil until the right conditions are present for germination. These plants tend to thrive in areas with ample sunlight, fertile soil, and plenty of water. Winter annuals will even go dormant in the cold months and attack your lawn as soon as spring arrives, well before your lawn even has a chance to get established.
- These plants only survive for one season and do not have enough time to develop overly complex root systems. For this reason, seed dispersal is the main way annual grassy weeds spread.
Perennial grassy weeds, on the other hand, may live for two or more years, and they can often thrive throughout multiple seasons. While some perennials can survive unfavorable conditions, such as drought or freezing temperatures, others prosper under more favorable conditions with adequate sunlight and moisture. Perennial grassy weeds often reproduce by using underground root systems to spread from one area to another, sometimes over great distances. Surviving through multiple seasons means these weeds have more time to develop roots (even deeper taproots), tubers, and runners all across your lawn.
- In addition to spreading through rhizomes and stolons, perennial grassy weeds can also produce seeds; however, this is usually a secondary method of reproduction. The strong, invasive roots of perennial grassy weeds are the real troublemakers!
Prevention
Taking the necessary steps to ensure your lawn is at its best will keep any weeds from taking root. The seeds of these unwanted weeds can easily find their way to your lawn, be it through neighboring lots, tracking it onto the grass from your shoes, and even sneaking in grass-seed mixes. Keeping your lawn in optimal shape through general maintenance and performing the following actions will go a long way to keeping your lawn free of nuisance weeds.
- Aerating compact soil. This practice allows oxygen and nutrients to penetrate the soil, encouraging dense growth of healthy turf grass and little room for weeds to sprout.
- Fertilizing your lawn keeps it from retaining too much nitrogen, which grassy weeds love.
- Watering deeply and consistently will give the deep roots of your turf grass a chance to get the hydration they need to grow and thrive. The shallow roots of the grassy weeds would have less of a chance of taking nutrients from healthy grass
- Mowing high will crowd out any seedlings trying to emerge.
- Using mulch on garden beds also keeps any weeds from growing by blocking them out.
- Treating your lawn with pre-emergents is another solution on keeping pesky grassy weeds from taking root and spreading.
