Quackgrass vs Crabgrass: Differences & What They Look Like

Confused about the grass weed that has invaded your garden? Then we have it sorted out for you. Grassy weeds can pose to be a big obstacle in growing a healthy lawn. These stick out and mess with the aesthetics of your lawn. Quackgrass and Crabgrass are the main culprits, and since they both look very similar, it gets difficult to identify one from the other. However, this is problematic because you need to buy herbicide labeled for the particular grassweed only. This means that you cannot use a quackgrass herbicide to kill crabgrass and vice versa.

In this article, we go in-depth to explain how to identify each of these weeds showing you the differences between quackgrass vs. crabgrass, so you know which weed you are dealing with. It will, in turn, let you control your weed and get rid of these stubborn grasses.

Identify Quackgrass

Identify Quackgrass

Quackgrass is a cold season perennial weed, and it is hardy. This means that the weed comes back year on year. In some climates, the weed can stay green all through the year. The plant is not a native. It is reproduced from rhizomes and seeds. The rhizomes are the long stems underground, and these dive to as low as six feet below the ground surface.

Quackgrass is also known as couchgrass, Agropyron repens, or Elymus repens. The features that let you identify this grass are:

  • It has hairless stem sheaths and seedling leaves.
  • It has hairless stem sheaths and seedling leaves.
  • It has hairless stem sheaths and seedling leaves.
  • It has hairless stem sheaths and seedling leaves.

A major problem when it comes to getting rid of quackgrass is that you may cut the rhizome below the ground when you till the land. This leaves the remaining pieces behind that start to eventually grow and then spread both below the surface and above it. It is this nature of the weed that makes it very difficult to control it. Rounding up helps kill the quackgrass weeds individually, but if your lawn has been invaded extensively, this is a challenge. It affects the lawn grass and the crops that are native to the field.

You can use weed killers or repeat mowing to a shallow height in the spring season. It is about timing and repeating the process. Quackgrass survives on the food stored in its roots, so if you mow the ground and spray the leaves in the early spring, this does not let the weed build its food supply in its root. Regular spraying and mowing starve the roots.

Identify Crabgrass

Identify Crabgrass

Crabgrass is an annual weed, and it grows from its seed in warm weather. Those staying in the cold region will not spot the crabgrass until summer sets in. Some of the crabgrass weeds are native, while others have been introduced. Both of these are a cause of concern. The non-native crabgrass with a smooth texture is known as the Digitaria ischaemum. The other is hairy and is known as the Digitaria sanguinalis.

Crabgrass is opportunistic by nature as it takes over the bare spots, not letting anything else survive. It can grow in areas where the soil is not fertile. It does not need any pH balance, nor does it need a lot of moisture. In short, it can grow in any area where the lawn grass has weak health. It immediately takes over the areas in the warm months when the cold season grasses struggle.

The name of this weed is because of the shape of its roots. The roots grow low in the ground, and its stem sports from the center of its clump. These look like the legs of a crab. The weed is devastating for your lawn. Crabgrass thrives and dominates your lawn in a short period. You need to follow the correct control measures, without which it becomes impossible to break the weed’s growth cycle and get rid of it. Here are the features that let you identify the crabgrass.

  • Crabgrass will sprout in the warm season since the weed adapts to the environment very fast. It makes it difficult to identify the crabgrass. They could be smooth, hairy, long, or short.
  • Crabgrass will die in the winter months, leaving back its flat and brown blades. Every crabgrass plant will reproduce through its seed, and these are viable throughout the years. The weed reproduces from its seed.
  • Eradicating crabgrass using chemicals is effective, but these also come with serious drawbacks. Some of the pre-emergent will affect the other grasses as well after application. Therefore the desirable grasses are also inhibited when you treat crabgrass with the chemical treatment. Corn gluten may be used because of its organic nature. It does not inhibit the grass seed, but it does not have the same effect in eradicating grass seed. The post-emergent weed killers are effective, too but have to be used in advance.

Quackgrass or Crabgrass – Know the differences

There is a lot of similarity between quackgrass and crabgrass, but they are different from each other. When it comes to similarities, crabgrass and quackgrass have thick and coarse leaves. They usually thrive in gardens along with some common grasses. However, their similarities end right here.

  • Quackgrass is a perennial that survives in the cool season, and crabgrass is an annual that survives in the warm season. Both the weeds are different in how they spread, and there are different solutions to eradicating them from your garden, especially in the short term. The long-term solutions to get rid of both the weeds are pretty much similar.
  • The roots of crabgrass are shallow and have a crab-like structure. The roots of the quackgrass from rhizomes grow horizontally and go deep into the soil. Both the weeds are incapable of thriving in a shaded and thick garden.
  • Quackgrass reproduces from its rhizomes that are under the ground, and these rhizomes grow continually. Crabgrass roots form a structure like a crab that stays shallow in the ground.
  • Crabgrass grows in the warm season and is active in the warm and tropical climate. Quackgrass is a perennial grass that survives in the cool season. The best method is to break its germination cycle to complete it maturely to get rid of the crabgrass. It is difficult to control quackgrass because it needs chemical and mechanical treatments as well as other preventive methods.
  • The shoots of crabgrass grow to form stumps in the form of the star shape. The quackgrass stems grow singly and they populate the area.
  • The leaves of crabgrass grow independently from its stem. The leaves of quackgrass from auricles and these then hooks around its stem.

Controlling quackgrass

  • Being a cold season perennial, it is tough to get rid of quackgrass. The same root can produce different leaves from one year to the other. When the conditions are right, these grow and spread in the lawn. Crabgrass will survive well in tall lawns because tall leaves let the root system develop stronger. Mowing at 3 inches is a great way to get rid of the quackgrass.
  • Applying a non-selective herbicide helps. Unfortunately, some chemicals target the crabgrass, but there are none for quackgrass. Chemical control of quackgrass is possible only through the non-selective herbicide.
  • Mechanical control by hand pulling is effective if the infestation is not very severe. Plowing, disking, and cultivating also helps.
  • Mulching helps to control quackgrass. Since the grass does not grow well in shady areas thus applying around a three-inch layer of mulch helps to prevent the weed from sprouting

Controlling crabgrass

  • Choke the shoots, which can be done by adequately fertilizing the lawn.
  • Inhibiting the soil condition will inhibit the growth of this weed.
  • Using pre and post-emergent herbicides are some best ways to kill crabgrass.
  • Uprooting helps too but make sure to dispose of the stem carefully so that the seeds do not spread.


Both quackgrass and crabgrass are invasive weeds that can turn your soft and pristine lawn into a complete mess. It gets difficult even for a professional lawnmower to get rid of these weeds. The grasses are clumpy and tough and can evade some of the sharpest tools. It gets difficult to remove these weeds at times, so some lawn owners just let them stay. However, that may not be necessary if you know how to identify them and are aware of the methods of getting rid of these troublemakers. However, the first step is to identify one from the other, without which the treatment method will not work. Since eradicating both the grasses is different, first, understand which grass it is and then use the appropriate method to eliminate it.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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