Dallisgrass vs. Crabgrass: Why Proper Identification Can Save Your Lawn (and Your Wallet)
Every summer, we get calls from homeowners who are convinced they’ve got a crabgrass problem.
They point to a bright green clump of grass that’s growing twice as fast as everything else in the yard and ask us one simple question:
“What do I need to spray?”
More often than not, our answer surprises them.
“That’s not crabgrass. It’s dallisgrass.”
It’s an easy mistake to make. Both are grassy weeds that seem to explode during the heat of summer. But they’re very different plants, and confusing one for the other often leads to wasted money, frustration, and another season of looking at the same ugly clumps.
We’ve seen homeowners apply pre-emergent, try multiple store-bought weed killers, and wonder why nothing changed.
The answer is simple.
They were treating the wrong weed.
What Is Dallisgrass?
Dallisgrass (Paspalum dilatatum) is a perennial grassy weed that commonly invades lawns throughout the Carolinas.
Unlike crabgrass, which completes its life cycle in one growing season, dallisgrass survives year after year because of its large crown and extensive root system beneath the soil.
That means mowing doesn’t slow it down.
Neither does winter.
Once a mature plant becomes established, it continues returning every growing season unless it’s physically removed or completely killed.
That’s why we encourage homeowners to deal with it early rather than hoping it’ll disappear on its own.
How to Identify Dallisgrass in Your Lawn
One of the easiest ways to identify dallisgrass is by looking for the grass that simply doesn’t match the rest of your lawn.
When we’re walking a property, we usually notice it before we ever bend down for a closer look.
The first clue isn’t the seedhead.
It’s the way the lawn looks.
You’ll often see one bright green clump sticking up above everything else just a few days after mowing.
Look for these characteristics:
- Dense clumps instead of grass spreading evenly across the lawn.
- Wider, coarser blades than your surrounding turf.
- Grass that grows noticeably taller just days after mowing.
- A brighter or lighter green color that contrasts with the rest of the lawn.
- Upright growth from a central crown instead of growing flat across the ground.
- Tall seedheads with several finger-like branches later in the summer.
The photo below is a great example.
Notice how the coarse blades grow upright in a tight clump and stand above the surrounding turf. The lighter green color and faster growth are often the first signs homeowners notice.
One thing we hear all the time is:
“My lawn was cut three days ago, but these patches are already sticking back up.”
That’s classic dallisgrass.
Dallisgrass vs. Crabgrass
Although they’re often mistaken for one another, these weeds behave very differently.
Getting the identification right is the first—and most important—step in choosing the right treatment.
Why Pre-Emergent Doesn’t Work on Dallisgrass
This is probably the biggest misconception we see.
Many homeowners assume that if they applied pre-emergent in the spring, they shouldn’t have any grassy weeds.
Unfortunately, that’s not how pre-emergent works.
Think of it as a barrier in the soil.
Its purpose is to stop new weed seeds from germinating.
That’s exactly why it’s so effective against annual weeds like crabgrass.
Dallisgrass isn’t starting from a new seed every spring.
The plant you’re seeing today already survived last winter.
Its crown and root system are still alive underground, sending up fresh growth each season.
Since there isn’t a new seed trying to germinate, the pre-emergent has nothing to stop.
That’s why homeowners often tell us:
“I put down pre-emergent, but this weed keeps getting bigger.”
If it’s dallisgrass…
That’s exactly what we’d expect.
Why Dallisgrass Is So Difficult to Kill
At first glance, dallisgrass doesn’t look intimidating.
It’s just a clump of grass.
But beneath the soil is a tough crown that stores energy and allows the plant to recover.
We’ve seen homeowners spray it once, watch the leaves turn brown, assume the problem is solved…
…only to see fresh shoots emerge a few weeks later.
Unless the entire plant is eliminated, mature dallisgrass often comes back.
That’s why simply burning off the leaves usually isn’t enough.
The Two Most Effective Ways to Control Dallisgrass
Unfortunately, there isn’t a selective herbicide that consistently removes mature dallisgrass from every lawn without affecting desirable grass.
That leaves two proven options.
Option 1: Spot Treat With a Non-Selective Herbicide
This is usually the most reliable long-term solution.
The downside?
A non-selective herbicide kills everything it touches, including your lawn.
After treatment, you’ll typically:
- Allow the dallisgrass to die completely.
- Remove any dead material if needed.
- Topdress the area.
- Allow healthy grass to spread back or install fresh sod.
While nobody enjoys creating a temporary brown spot, it’s often much easier to repair one small area than allow several large clumps to continue spreading.
Option 2: Dig It Out
Sometimes old-fashioned elbow grease is the answer.
As we joked in our video:
“Get your grandmother’s shovel… a pitchfork… your hands… even your teeth if you’ve got to.”
(We definitely don’t recommend using your teeth.)
The point is that removing dallisgrass means getting the entire crown and root system out of the ground.
Leave part of the crown behind, and there’s a good chance it’ll return.
When Should You Treat Dallisgrass?
The sooner, the better.
We’ve found that homeowners often wait because they hope the weed will disappear after mowing.
It won’t.
Small clumps are significantly easier to manage than large, mature ones.
Waiting means:
- Larger dead areas after treatment.
- More lawn repairs.
- More seedheads.
- More opportunity for the weed to spread.
Early identification almost always produces the best outcome.
Repairing Your Lawn After Dallisgrass Removal
Removing dallisgrass is only half the job.
The next step is helping your lawn recover.
For Bermuda grass, surrounding runners will often spread back into small treated areas with proper watering and fertility.
For tall fescue, the repair usually requires fall overseeding or replacing the damaged section with new sod because fescue doesn’t spread the same way.
Choosing the right repair method depends on your turf type and the size of the affected area.
Common Mistakes We See Homeowners Make
Over the years, we’ve noticed the same mistakes repeated again and again.
❌ Assuming every grassy weed is crabgrass.
❌ Spraying products without first identifying the weed.
❌ Expecting pre-emergent to eliminate established plants.
❌ Waiting until the lawn is covered with large clumps.
❌ Treating symptoms instead of identifying the root problem.
Proper weed identification saves both time and money.
Professional Turf Care Starts With Proper Identification
One of the biggest differences between professional turf care and guessing is knowing exactly what you’re treating before applying a product.
Not every grassy weed requires the same approach.
Some respond well to selective herbicides.
Some are prevented with pre-emergent.
Others—like dallisgrass—require a completely different strategy.
That’s why we never recommend a treatment until we’ve identified the weed first.
In many cases, spending a few minutes correctly diagnosing the problem prevents homeowners from wasting an entire season fighting the wrong battle.
Not Sure What That Weed Is?
If you have patches of grass that are brighter green, growing faster than the rest of your lawn, or sticking up only a few days after mowing, don’t automatically assume it’s crabgrass.
It may be dallisgrass.
And if it is, the treatment plan is very different.
We’re always happy to help homeowners identify what they’re dealing with before they spend money on products that may not solve the problem. Sometimes the most valuable service we provide isn’t the treatment itself—it’s making sure the diagnosis is right from the start.
Because healthy lawns don’t happen by accident.
They start with knowing exactly what you’re growing.
Contact Sprout Tech Turf Solutions today to schedule your lawn evaluation and discover how professional turf care can make a lasting difference for your property.
