Identifying a weed puts you one step closer to removing it, and crabgrass makes this difficult. The illusive crabgrass has caused a lot of gardeners angst day and night, to the point where simply thinking about dealing with it on your lawn creeps many of us out.
Besides claiming the title of hardest weed, crabgrass has an astonishing ability to take on multiple identities. So, if you suspect crabgrass on your lawn, especially now that spring has sprung, you may be mistaken.
Read on to learn more about weeds that look like crabgrass, but first, learn more about crabgrass.
What does crabgrass look like?
This weed will soon take over your lawn and cause problems.
To manage it efficiently, you must first recognize it correctly. Even though it looks similar to other weeds, several distinguishing characteristics will assist you in identifying it in your yard so that you can treat it correctly early.
Crabgrass leaves are usually yellowish-green to lime green in colour and may have a white stripe running through the centre. The blades are about a pencil’s thickness, 12 to 14 inches wide and 5 inches long.
If you look closely, you will observe that the blades emerge directly from the stem and expand outwards, like crab legs. The leaves could also be hairy or smooth.
The crabgrass stem is winding and has a purple tint at the base. As the plant matures, the stems become heavy and fall, creating side roots. When not mowed, it produces its trademark growth pattern of sprawling mats of grass that eventually cluster.
Weeds that look like crabgrass
Many of us confuse Quackgrass and crabgrass because they have nearly identical physical appearances; nine times out of ten, we run to our local garden store to get a crabgrass preventer when you have Quackgrass on your lawn. But the reality is that these two are different and easily distinguished.
To begin with, Quackgrass is a cold-hardy perennial weed that grows from seeds and thin, creeping, deep-lying underground rhizomes, making it a worthy foe that is both irritating and difficult to eradicate.
On the other hand, the opportunistic crabgrass is a warm-season annual weed that develops exclusively from seeds and dies throughout the winter due to its weak roots.
The misleading nature of these two weeds is that they both have thick, coarse leaves, but when you look closely at the Quackgrass, you will discover that the leaves cling around the lower stem, whilst the crabgrass leaves grow independently from the stem.
To recognize Quackgrass early, look for these finger-like extensions called auricles that hook around the stem.
A growth pattern is another technique to determine the difference, although the difference is only visible when the grass is mature. The crabgrass’s mature growth pattern has the leaves and stems resting horizontally, giving it a flattened aspect.
You will observe its famous star-shaped stumps with visible prostate growth, whilst the Quackgrass has an upright growth forming singly to populate your yard.
Controlling Quackgrass is difficult due to its deep rhizomes, and most herbicides, unless you use roundup, will have little effect on it. Additionally, eliminating the rhizomes will ensure that your lawn is free of Quackgrass.
2. Coarse fescue
I recently received an email from one of my clients who was frustrated with his failure to remove the crabgrass on his lawn. I requested him to give a clear image of the weed, and it turned out that he was dealing with coarse fescue rather than crabgrass.
Coarse fescue is a perennial species that grows in bunches and has wide blades, deceiving many homeowners into thinking they are seeing their old adversary, crabgrass.
If you look closely, you’ll see that the coarse fescue blades are wider and coarser to the touch than the crabgrass and Quackgrass.
In contrast to the crabgrass’s yellowish-green leaves, the coarse fescue grass expands energetically and swiftly creates dark green with glossy lower surface leaves.
The coarse fescue stays green most of the year, forming colonies in clear, well-defined borders thanks to its tillering and short rhizomes limiting how far each colony expands, unlike the crabgrass that loves to sprawl. Just like the Quackgrass, coarse fescue can be controlled effectively using roundup.
See also: Is wood sorrel the same as clover?
The Dallisgrass has a similar appearance to crabgrass, but there are some significant differences.
To begin with, the Dallisgrass is taller and more upright. It also appears on lawns as circular clusters with thick short rhizomes. Because of its clumping nature, Dallisgrass masquerades like crabgrass most of the time.
The Dallisgrass’s colour unlike crabgrass, which has a yellowish-green tinge, this weedy grass has a deeper tone. The seed heads of the two are a unique and quick way to tell them apart.
The crabgrass seed head grows on the top of the stem and is small and fine, whereas the Dallisgrass seed head grows on the side of the stem and is larger with small black spots.
Dallisgrass is more tenacious than crabgrass in terms of management. Its perennial nature and capacity to resurface from deep root systems make it a formidable foe.
As a result, utilizing preemergent herbicides to suppress dallisgrass will be a waste of time. A selective herbicide, on the other hand, will be effective after two applications.
Goosegrass is an annual weedy grass with stems radiating from its centre and a low-growing habit that many homeowners confuse with crabgrass. Because of this striking resemblance, this grass has been dubbed the silver crabgrass, even though it is not a variety of crabgrass.
It is, however, simple to distinguish between goosegrass and crabgrass. Goosegrass has a white or silver core and darker-coloured leaves than crabgrass. Furthermore, unlike crabgrass, its roots do not contain nodes at the stem.
Goosegrass, like crabgrass, is easy to control with preemergent herbicides, and its shallow roots allow for manual plucking. However, it is difficult to control with low mowing because it grows slowly.
See also: Common invasive grass types
When you notice crabgrass in the early spring, chances are you’re dealing with one of the grasses indicated above.
Always keep an eye on the weedy grass’s colour and growth pattern. You stand a higher chance of saving your lawn if you can determine the difference between weeds that look like crabgrass.
University of Maryland Extension: Lawn weeds
UC Weed Science Managing: Weedy grasses