Dallisgrass vs Crabgrass – Differences and Identification

If you’re a homeowner, you know your pride and joy is having a lush, green lawn that is the envy of your neighbors. However, it’s not an easy task maintaining your lawn and sometimes you may come across the dallisgrass or crabgrass growing on your lawn.

Dallisgrass and crabgrass are both weeds that find their way onto your lawn and disrupt the beauty of your lawn. These two weeds are clumping grasses and may look similar, but there are a few differences you’ll find between the two weeds.

Type of weed


Control and prevention


Hollow leafless stalk, serrated comb, and tooth-like leaves, yellow petal flowers mature to white puffballs

If only a few dig them out to remove by hand, pour boiling water, or use a broadleaf herbicide

Yellow nutsedge

Grass-like leaves with a v-shaped cross-section, golden-brown flower spikelets, hairless triangular stem

Remove by hand, use sugar, use a herbicide


Arrow-shaped leaves, white/blue/purple flowers, thick stem

Cut it at ground level, pour boiling water, use a non-selective herbicide


Wide leaves, rough blades, thick white roots

Regular overseeding your lawn, dig out all the roots, frequent mowing, spot spray a non-selective herbicide


This is a warm-season perennial grass that can reach up to 5 feet. It’s a robust, clumping, coarse-textured grassy weed that invades all types of turfgrass. It grows in an ever-enlarging circular clump that gets so large at times that the center dies and the outer rings continue to grow. It’s a difficult weed to control and it thrives in clay or sandy soils. Dallisgrass reproduces by very short rhizomes and seeds in the summer and tends to do very well where there’s lots of foot traffic and your desired grass gets beat down. This makes this unsightly grass weeds a nightmare for your turfgrass. Most people confuse the dallisgrass with crabgrass.

How to identify Dallisgrass

  • Dallisgrass grows fuller and taller while crabgrass grows outward.
  • It has a distinguishing clump that gradually grows circular and its short rhizomes increase its diameter and store carbs.
  • It grows in a way that is difficult to control because it can be difficult to pluck out of the grass because of its fibrous thick roots which can reach up to 1 m deep.

How to kill dallisgrass

  • You can control dallisgrass by maintaining a healthy, dense turf through ensuring you properly water, mow, and fertilize your lawn. Also quickly fill the bare spots with sod or seed to prevent the weed seeds from invading your lawn.
  • Also, use pre-emergent control herbicide that is toxic to crabgrass can also be effective in killing dallisgrass. Ensure your water to allow the herbicide to penetrate the soil.
  • Lastly, you can also post-emergent treatments like digging the weed out which is labor-intensive, or using a post-emergent herbicide that you would use on crabgrass and apply it several times at 2-3 weeks interval to prevent regrowth.


This is a summer annual weed grass which means in most climates it only grows once a year produces seeds then dies off. It has wide flat blades and produces long flower clusters and lots of seeds per season. Although crabgrass is invasive, it’s not competitive so it will only appear when your lawn is weak and unhealthy. It grows outward in a roughly star-shaped pattern that tends to grow close to the ground. It spreads through new shoots of grass that grow a bit far from the center of the clump and will continue to spread to more than a foot in diameter if left unchecked.

There are two different types of crabgrass, smooth crabgrass with no hairs and the hairy type with hairs all over the plant.

How to identify crabgrass

  • The blades are angled out from the stem and grow continuously as new blades appear.
  • As it grows, the seedlings develop side shoots that develop into separate branches.
  • The leaf blades are long and a bit wide.

How to prevent crabgrass

  • One of the best ways of preventing crabgrass from growing on your lawn is to ensure the lawn is growing thick and healthy without any bare spots.
  • Also, use a pre-emergent herbicide to create a protective barrier in your lawn that will prevent the growth of crabgrass seeds.
  • A post-emergent herbicide will kill all the crabgrass already growing on your property.

Differences between dallisgrass and crabgrass

Type of weed

Dallisgrass is a perennial weed grass that is difficult to control because it doesn’t die once the season ends, it just stays dormant. However, crabgrass is an annual weed grass whose lifecycle only lasts one season so it’s easier to control than dallisgrass.

Mode of spreading

Dallisgrass is a course-textured clumping grass that spreads from short thick rhizomes that continue to grow a deep underground stem. The clumps are thicker and stiffer than other types of grass which can trip you if you’re walking across your lawn. However, crabgrass spreads using the same method but it spreads using a star-shaped pattern that grows to form a thick mat and develops side shoots that become separate branches once they grow.

Where it grows

Dallisgrass thrives in sandy and clay soils and will grow rapidly in nitrogen fertilizer to twice as much as your regular turf grasses which can create an unsightly turf. It can invade all types of turf grasses and spread rapidly which makes it very hard to control. The crabgrass on the other hand only grows where there are bare spots on your lawn so growing a thick lawn grass can be effective in controlling it.


Since it’s difficult to get rid of grass weeds like dallisgrass and crabgrass once they become established, it’s best to ensure you always keep your lawn thick and healthy. Also, keep an eye on your lawn to check for weeds and act fast to treat them.


Will vinegar kill dallisgrass?

Using vinegar at home can kill dallisgrass in no time, however, be careful when applying the vinegar on the leaves.

What’s so bad about crabgrass?

Crabgrass is an opportunistic weed that will usually grow in bare or thin parts of your lawn and can also crowd-out the good grass that has been weakened by mowing too short, affected by the disease, insects, or other problems.

Leave a Comment