How to Get Rid of Quackgrass: Wipe, Do Not Spray

Quackgrass is the weed that makes people believe their weed killer is faulty.

They buy a well-reviewed lawn herbicide, spray the patch, watch the dandelions around it curl and die — and the quackgrass does not change colour. Nothing is wrong with the product. It was never going to work, and no product on that shelf will.

Is It Really Quackgrass?

Get this wrong and every decision after it is wrong too, because the three plants people confuse with quackgrass each want a completely different treatment — and one of them is treated in a different season.

Against crabgrass. Crabgrass is a summer annual. It germinates in spring, dies at the first hard frost, and has no underground runners at all, which is why a pre-emergent stops it before it starts. Quackgrass is a perennial that overwinters and returns from stems already in your soil, so a pre-emergent barrier is irrelevant to it — the plant is not germinating, it is regrowing. If you have been applying pre-emergent and the patch keeps coming back in the same place, that alone is close to a diagnosis. Our crabgrass guide covers the annual case.

Against bermudagrass. This is the confusion worth being most careful about, and the giveaway is above ground rather than below it. Bermudagrass (Cynodon dactylon) spreads by stolons as well as rhizomes — runners you can see travelling across the soil surface and lift with a finger. Quackgrass (Elymus repens) has no stolons; MSU describes it simply as an “erect, rhizomatous perennial”, so everything it spreads with is underground. The second tell is the winter: bermudagrass goes fully dormant and straw-brown in cold weather, which is why southern lawns look dead in January. If your invader browns off completely and you can lift visible surface runners, you are on the wrong page — killing bermuda grass in a fescue lawn is a different problem with a different programme, and in much of the South bermudagrass is the lawn rather than the weed.

The positive test. Two features settle it, and neither needs a hand lens.

Wisconsin Extension names the first:

“In addition to rhizomes, quackgrass can be identified via long, slender, clawlike auricles, which wrap around stems near the base of the leaf blades.”

MSU’s plant profile puts the same feature more precisely: “Clasping, clawlike auricles are present at the collar region.” Bend a blade back where it joins the stem and look for two pale, claw-shaped projections clasping around it. Once you have seen them they are unmistakable — and this is a positive identification rather than a process of elimination, which is what makes it worth the thirty seconds.

The second is colour and width. Wisconsin notes quackgrass’s “wider, blue-green leaf blades”, and that mixed into a lawn they “stand out and look weedy” — which is usually what made you look in the first place.

And if you dig one up, MSU tells you what you are looking at: “Plants spread by thin, yellowish to white, sharp-tipped rhizomes.” Those white, pointed underground stems are the whole problem, and the next section is about why.

Why No Lawn Herbicide Works

The reason is not that quackgrass is unusually tough. It is that selectivity has nothing to work with.

A selective herbicide exploits a difference — between a broadleaf plant and a grass, between a sedge and a turfgrass, between a warm-season and a cool-season species. Quackgrass is a cool-season perennial grass sitting in a lawn of cool-season perennial grasses. Wisconsin Extension states the outcome:

“Control options are limited because the weed species are very similar to the lawn species, so selective herbicides are rarely an option.”

So the entire three-way broadleaf aisle — the products that handle dandelions, clover and creeping charlie — is irrelevant here. Those products are built to spare grasses, and quackgrass is a grass. Buying one for this job is not a weak choice; it is a purchase with a guaranteed outcome of nothing.

That leaves non-selective chemistry, which kills whatever it lands on. Which is why this article is mostly about how you apply it rather than what you buy.

Pulling It Makes It Worse

This is the part that costs people a season, because it feels like progress while it happens.

Quackgrass spreads by rhizomes, and a rhizome is not a root — it is a stem, with buds along it, each capable of producing a whole new plant. Wisconsin Extension gives the consequence in one line:

“Rhizomes breaking off and remaining in the soil are likely to propagate more quackgrass.”

So an afternoon of enthusiastic hand-weeding takes one connected plant and turns it into a dozen disconnected ones, each with its own bud and its own growing point, all now spread across a wider area than the patch you started with. MSU Extension’s verdict on mechanical removal generally:

“Due to the perennial nature of quackgrass and its well-developed rhizome system, it is very difficult to remove by mechanical means.”

Digging can work, but only as a genuinely different job from weeding. MSU describes it as “digging up the offending patches, including several inches of soil and replacing with new topsoil and reseeding” — and then adds a caution that is worth reading twice:

“However, the rhizomes of quackgrass can grow 6 to 8 feet deep in the ground, and these rhizomes could potentially ‘push’ new plants to the surface.”

Take that as MSU’s own assessment of how deep the reservoir can run. The practical point stands regardless of the exact figure: if you dig, you remove soil and every white rhizome in it, and you still may not have got all of it.

Wipe It, Do Not Spray It

Here is the technique that changes this from an impossible problem into a manageable one, and it is the part most guidance skips.

A non-selective herbicide kills whatever it contacts. Sprayed, it contacts a cloud of things — the quackgrass, the lawn beside it, and whatever the drift reaches. But it does not have to be sprayed. Iowa State Extension:

“They can also be applied with a sponge and wiped onto the weed leaves to prevent collateral damage to nearby plants.”

Load a sponge or wiping applicator with the mixed solution and draw it along the quackgrass blades. The herbicide goes exactly where you touch and nowhere else. It is slower than spraying and it turns a non-selective product into an effectively selective one — not because the chemistry changed, but because you did the selecting.

Three things decide whether this works:

• Squeeze the excess out first. A loaded sponge drips, and a drip is a dead spot in the lawn that you will be looking at for months. The sponge should be damp enough to wet a blade, not wet enough to run.
• Pick a still, dry day. No wind to fling droplets off an overloaded sponge, and no rain for the rest of the day — the product has to stay on the leaf long enough to be taken into the plant. Our guide on rain and weed killer has the rainfast intervals.
• Wear the gloves the label specifies. Wiping puts your hand nearer the solution than spraying does. A change in application method does not change the personal protective equipment the label requires.

Where a patch is large enough that wiping every blade is unrealistic, Iowa State’s alternative is to spray and physically shield what you want to keep — “protect garden plants with barriers like buckets or boxes to further reduce problems with drift.” An upturned bucket over a plant, or a sheet of cardboard held against the lawn edge, does the same job as the sponge at a coarser scale.

One detail worth taking from the label rather than from advice: quackgrass sits in the tough weed / perennial column of the rate table, not the general weed column. On the label read for this article that meant a noticeably higher concentration for the same volume of water. Mixing at the annual-weed rate is a common reason a treatment half-works, which on a rhizomatous perennial means it regrows. How to read a pesticide label covers finding that table on your own bottle.

Once Is Not Enough

Plan for two applications from the beginning, and treat anyone who tells you one kills it at the root permanently with polite suspicion.

Glyphosate is systemic — it moves through the plant rather than just burning the tissue it touches — and that really is what gives it a chance against a rhizome network. But moving through a network that large, from the few blades you wiped, is imperfect. Both programmes say so. MSU:

“In our opinion, you will need to apply the Roundup twice. Make the second application 14 days after the first.”

Iowa State frames the same thing as a decision rule rather than a schedule:

“If the treated areas are not dead in 2 to 4 weeks, a second application is necessary.”

The second pass catches what regrew from rhizome buds the first application did not reach. Skipping it is the single most common reason a patch that looked dead in September is a patch again in May.

Then Fill the Hole the Same Week

Killing quackgrass leaves bare soil, and bare soil does not stay bare. Whatever seed blows in next takes it — and you will have spent a month of effort to trade one weed for another.

Both programmes put the repair on a clock. MSU:

“Seven days after the second application you can rough up the area and sow your new grass seed.”

Iowa State agrees on the interval — “treated areas can be seeded or sodded seven days after the application” — and both put the whole operation in late summer for the same reason our overseeding guide does. Wisconsin’s version:

“Apply in August so the area can then be reseeded in late August or early September.”

So count backwards. Two applications 14 days apart, plus seven days, is three weeks before you can seed. If your seeding window opens at the end of August, the first wipe goes on in the first week of the month.

The Option Nobody Sells You

There is a fourth approach, it costs nothing but effort, and it comes from MSU rather than from a bottle: make the lawn win.

“Many folks have effectively ‘eliminated’ quackgrass by masking its presence in the lawn. This is usually accomplished by increased nitrogen fertilization and increased mowing frequency.”

Note the quotation marks MSU puts around eliminated — they are being honest that the quackgrass is still there. What changes is that it stops being visible: a vigorous, frequently mown lawn closes over it, and the quackgrass darkens and blends rather than standing out as a coarse pale patch. MSU’s reasoning is that “the quackgrass only has a competitive advantage when the desirable grass sits idly by.”

Their programme is specific:

“Fertilizing your lawn with 0.25 to 0.5 pounds nitrogen per 1,000 square feet every two weeks during the growing season.”

With one condition attached that matters more than it sounds: “If this ends up being one of those dry summers, you would definitely want to suspend this program because unless you’re irrigating, the turf will not be able to use the nitrogen.” Nitrogen applied to grass that has no water to grow with does not help the lawn and does not disadvantage the weed. Our fertilizer guide has the rate arithmetic for converting that into bags.

MSU also lists solarization for people who want the patch gone without chemistry: clear plastic “fastened securely to the ground over the quackgrass areas”, cut slightly larger than the patch, left “in place for five to seven days in the spring or summer when the weather is nice”, then reseeded. It kills the lawn under the plastic too, so treat it as a smaller, slower version of the same clear-and-reseed job.

And their last option is the one no product page will ever offer you:

“Option 4: Do nothing. Obviously, quackgrass is green and takes mowing. You may decide after looking at the other options that it is better than bare soil.”

If the patch is at the back fence rather than by the patio, that is a legitimate answer rather than a defeat.

The Honest Summary

1. No selective herbicide controls quackgrass in a lawn. Wisconsin: the weed and the lawn are too similar. Every broadleaf product will leave it standing.
2. Do not pull it. Rhizome fragments left in the soil become new plants, so weeding multiplies the patch.
3. Wipe, do not spray. A sponge loaded with a non-selective puts the herbicide only where you touch it. Squeeze out the excess — a drip is a dead spot.
4. Mix at the perennial rate, not the annual one. Quackgrass is in the tough-weed column of the label.
5. Two applications, 14 days apart. One is the most common reason it comes back.
6. Seed seven days after the last one, in the late-summer window, or something else claims the bare ground.
7. Or outgrow it. Frequent nitrogen and frequent mowing make it blend in, which for a back corner may be all you need.