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Crab grass problem


How to Kill Crabgrass and Prevent it from Returning

Once crabgrass gets started in your lawn, those coarse, unattractive weeds seem to live and spread forever. But unlike lawn weeds that do live several years, crabgrass plants only live a single year. What they do in that year, however, has long-lasting consequences for your lawn. Understanding how crabgrass works and how to break its cycle can help you get rid of crabgrass and keep it gone.

  1. Understanding the Crabgrass Cycle
  2. Preventing Crabgrass Plants
  3. Timing Crabgrass Preventers
  4. Killing Existing Crabgrass Plants

Crabgrass is a warm-season annual that germinates, lives and dies all in the same year. But crabgrass problems don't end with the growing season. While they live, each crabgrass plant produces up to 150,000 seeds.1 Those seeds stay behind, ready to germinate the following spring and start the cycle all over again. Seeds that don't germinate right away can remain viable and stick around to germinate in future years.

Once crabgrass seeds germinate and plants emerge, mowing your lawn short won't stop the seeds. With its low-growing, crab-like growth, crabgrass can set seed when cut as low as 1/2 inch tall1 — that's much lower than recommended healthy mowing heights for any common lawn grass. Effective control requires preventing crabgrass seeds from ever becoming seed-producing plants.


Low-growing crabgrass seeds escape mowers.

With hundreds of thousands of crabgrass seeds potentially waiting in your lawn, preventing their successful germination is essential. Crabgrass preventer products use what are known as "pre-emergent" herbicides, which target germinating seeds before new shoots can emerge from soil.

Pre-emergents work by inhibiting seed germination and root development so that seeds can't become established plants. Highly effective preventers such as Pennington UltraGreen Crabgrass Preventer plus Fertilizer III 30-0-4 control crabgrass and other germinating broadleaf weeds. This premium product then continues preventing these weeds for up to five months, while it feeds your lawn grasses at the same time.

While crabgrass preventers target weed seeds, they can inhibit germination and establishment of lawn grass seed, too. Always follow label instructions regarding seeding and your specific preventer product. As a general rule, wait at least 60 days and at least two mowings before overseeding lawn areas where crabgrass preventer was used.


A single crabgrass plant can set up to 150,000 seeds in a season.

Because crabgrass preventers only work before crabgrass seedlings emerge through the soil, timing applications right is critical to success. Preventers must be applied before crabgrass seed germinates. Crabgrass seeds can germinate from early spring until late summer when soil temperatures are right.

In spring, crabgrass starts germinating when soil temperatures warm to 55 degrees Fahrenheit for four to five days in a row. 1 Most garden centers carry inexpensive soil thermometers that can help you track soil temps and time your preventer properly. If you live in northern climates, nature helps, too. Yellow-blooming forsythia shrubs reach full bloom at the same soil temperatures that signal crabgrass germination.

Once soil temperatures warm and germination starts, crabgrass seeds continue germinating until soil temperatures exceed 90 F. While some preventer products stop working after a short window in spring, Pennington UltraGreen Crabgrass Preventer plus Fertilizer III 30-0-4 keeps on preventing crabgrass and other broadleaf weeds as it feeds your lawn through those crucial months.


Once seeds germinate and crabgrass sprouts emerge, pre-emergents no longer work. Then it's time for "post-emergent" herbicides, which target plants instead of seeds. Crabgrass killers are designed to kill existing, actively growing crabgrass plants before they can produce more seed.

When using crabgrass killers or any herbicides, it's important to understand whether the product is a "selective" or "non-selective" herbicide. Selective herbicides target specific weeds or plant categories, such as grassy plants versus broadleaf plants. Non-selective herbicides kill all plant types, including lawn grasses and other plants you want to keep.

Because crabgrass is a grass, most combination herbicide and lawn fertilizer products, known as weed & feed fertilizers, generally won't kill it. These products typically include selective herbicides that kill broadleaf weeds, such as dandelions and other common lawn weeds, and keep grasses unharmed. Actively growing crabgrass in your lawn calls for selective, post-emergent herbicides, such as Image All-In-One Lawn Weed Killer or Image Herbicide Kills Crabgrass, that kill crabgrass and leave your lawn grass untouched.

Always read product labels carefully, and make sure the label lists your lawn grass type as approved. Some lawn grasses, such as centipede grass and St. Augustine grass, are susceptible to herbicides that don't harm other lawn grasses. Whenever treating lawn weeds with herbicides or weed & feed fertilizers, follow label instructions thoroughly, including safety precautions to protect pets, kids and adults.

When crabgrass threatens to disrupt your lawn, you can take control, break the cycle and prevent its spread. Pennington is committed to providing you with the finest in quality lawn and garden products along with expert advice to help you achieve the lush, healthy, weed-free lawn you desire.

Pennington is a registered trademark of Pennington Seed, Inc.

Image and UltraGreen are registered trademarks of Central Garden & Pet Company.

Sources:

  1. UMass Extension Turf Program, "Biology and Management of Crabgrass," University of Massachusetts Amherst, May 2011.
  2. Perry, Leonard, "Crabgrass Control," University of Vermont Extension.

Photo Credit:

  1. NY State IPM Program at Cornell University, CC BY 2.0
  2. NY State IPM Program at Cornell University, CC BY 2.0

How to Kill Crabgrass

By

David Beaulieu

David Beaulieu

David Beaulieu is a landscaping expert and plant photographer, with 20 years of experience. He was in the nursery business for over a decade, working with a large variety of plants. David has been interviewed by numerous newspapers and national U.S. magazines, such as Woman's World and American Way.

Learn more about The Spruce's Editorial Process

Updated on 11/22/22

Reviewed by

Kathleen Miller

Reviewed by Kathleen Miller

Kathleen Miller is a highly-regarded Master Gardener and Horticulturist who shares her knowledge of sustainable living, organic gardening, farming, and landscape design. She founded Gaia's Farm and Gardens, a working sustainable permaculture farm, and writes for Gaia Grows, a local newspaper column. She has over 30 years of experience in gardening and sustainable farming.

Learn more about The Spruce's Review Board

The Spruce

In This Article

Project Overview

Crabgrass (Digitaria) is a coarse, warm-season annual grass that easily infiltrates a turf grass lawn and is thus loathed by homeowners. Spreading by seeds, crabgrass grows in clumps with stems that radiate out from the center and resemble crab legs. This opportunistic grass is the nemesis of homeowners wanting to cultivate a manicured lawn, perennial flower beds, and meticulous walkways. It often appears in the spring and proliferates in the hot, dry conditions of the summer if it's not eradicated first.

In addition to natural and commercial herbicide methods, crabgrass can be pulled by hand. Using a garden weeder tool, completely remove all parts of the plant's root system after hand-pulling the upper part of the plant. Dig the tool deep into the soil surrounding the exposed part of the plant to remove excess roots that have spread under the soil line.

To control larger portions of crabgrass in your lawn, it's best to use pre-emergent herbicides before the plants sprout or apply organic methods after pulling these weeds by hand. Below, learn how to tackle crabgrass to keep your landscape in shape.

Identifying 9 Common Lawn Weeds

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Before Getting Started


It helps to familiarize yourself with the plant's life cycle to effectively eradicate crabgrass. When spring soil temperatures (at a depth of 2 to 3 inches) reach 55 to 60 degrees Fahrenheit, crabgrass seeds start to germinate. From mid-summer through fall, the plant produces more seeds in an attempt to increase its numbers. Once the first frost arrives, the plants themselves (but not the seeds) are killed.

If crabgrass is a problem in your yard, luckily, you have more than one arrow in your quiver to remove it:.

When to Kill Crabgrass

The proper time for attacking crabgrass depends on what method you are employing.

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How to Kill Crabgrass Organically

You don't really need chemicals for crabgrass control. While it's easy to kill crabgrass with herbicides, the best way to remove it and control it is by first pulling it, and then cultivating healthy new grass.

  1. Soak the Soil

    Water the problem area with a sprinkler or garden hose, then wait about 30 minutes to allow the water to soak in.

    The Spruce / Jayme Burrows

  2. Pull Out the Crabgrass

    Using a pitchfork or weeding tool, remove young crabgrass when it's big enough to rip out, roots and all. If you're working with a large patch, this could take a while. If the soil is moist enough, though, clumps of crabgrass may pull free if you simply gather the leaves in your hand and pull upward with stead pressure.

    The Spruce / Jayme Burrows

  3. Add Compost

    Add organic compost to the area in question. Work the soil so that it is thoroughly incorporated.

    The Spruce / Jayme Burrows

  4. Topseed with Turf Grass Seed

    Seed the area with grass seed, and then place a layer of weed-free straw over the top to maintain moisture and protect the seeds from being eaten by birds.

    The Spruce / Jayme Burrows

  5. Keep the Soil Moist

    Water the area multiple times daily, depending on moisture conditions. Make sure the soil is consistently moist until the seeds sprout.

    The Spruce / Jayme Burrows

  6. Switch to Deep Watering

    When the grass is long enough to mow, start irrigating the lawn more deeply and less frequently. Crabgrass is a notoriously shallow-rooted weed; if you water too frequently and for a short duration, it will help it thrive.

    The Spruce / Kevin Norris

  7. Mow the New Grass

    To maintain your new patch of grass, mow it high. This means leaving grass at a height of 2 1/2 to 3 inches tall. Doing so will allow the lawn grass to "protect its own turf," depriving crabgrass seeds of the light they need to germinate.

    The Spruce / Jayme Burrows

  8. Weed as Needed

    Throughout the season, pull any remaining crabgrass plants that sprout up. By next year, your yard should be free of it.

    The Spruce / Jayme Burrows

How to Kill Crabgrass With Pre-Emergent Herbicide

To successfully kill crabgrass with pre-emergent herbicides, timing is of the essence. Apply pre-emergent herbicides before germination, which usually coincides with the blooming of lilac bushes. Once you kill the weed from its roots, you can then reseed the area after a waiting period.

In early spring, check the weather and select a time to treat when a steady rain is in the forecast. Water actually activates pre-emergent herbicides.

Warning

Put on gloves and protect yourself with long pants and a long-sleeved shirt. Herbicides are toxic chemicals that can be absorbed through the skin. Herbicides should always be applied by spot-treating rather than broadcast spraying. Choose a windless, calm day for spraying crabgrass.

  1. Measure the Lawn

    Measure the lawn area and refer to package directions to mix the proper herbicide application amount.

  2. Apply the Fertilizer

    Spray or sprinkle the herbicide over the area in question. Make sure to apply it thoroughly and uniformly, taking care not to miss a spot.

  3. Reseed the Area

    Wait two to four months before reseeding the problem area, and then follow irrigation and mowing recommendations to prevent weeds.

How to Kill Crabgrass With Post-Emergent Herbicide

  1. Mix Herbicide

    If using a concentrated post-emergent herbicide, mix it with water, following the manufacturer's instructions for ratios for treating crabgrass. Some commercial weedkillers are rated for both broadleaf weeds and crabgrass, while others are formulated for broadleaf weeds only—these will not work on crabgrass.

    Pour the mixture into a pump-style garden sprayer.

    Tip

    If applied very carefully, a broad-spectrum herbicide such as glyphosate (RoundUp) will kill crabgrass. Take care not to allow the spray to drift, as this chemical will also kill desirable turf grasses. But with a large colony of crabgrass, sometimes the best strategy is to kill the entire area with glyphosate and then reseed or resod.

  2. Spray the Weed

    On a hot, sunny, windless day, spray the clump of crabgrass thoroughly,, making sure it is entirely saturated to the ends of the leaves. Unlike pre-emergent herbicides, post-emergent chemicals should be spot-sprayed directly on the weed, not applied broadly. Take pains not to allow the mist to drift onto garden plants, as these herbicide are toxic to many broadleaf plants.

  3. Observe and Repeat

    The crabgrass should begin to turn brown and die within a few days. But rainfall or watering can rinse the herbicide away, so repeated follow-up treatments are sometimes needed.

Tips for Killing Crabgrass

How to Seed a Lawn From Scratch

Top 5 Crab Grass Barriers Review & Buyer's Guide

Crabgrass is one of the most unwanted weeds on any lawn. This weed can spread quickly, so it's best to remove or kill it whenever you see it in your lawn. It is easily recognizable by its herbaceous appearance and broad leaves.

Crabgrass has tough stems that hold the seed heads at the tips. Each of its seeds, when ripe, can produce and distribute over a thousand seeds. It has a very high seed yield, which explains its rapid spread. Thus, without proper control, they can invade your lawn for months. nine0003

The good news is that there are various ready-to-use solutions that will easily and quickly kill crabgrass before it spreads and takes over your lawn. However, when choosing a grass killer, you should also consider your safety and the plants in your lawn.

In doing so, our team of experts tested and analyzed several products and compiled a list of the best crab killers on the market. To make sure we have the safest items, we've highlighted their best features and potential issues you may encounter while using them. So, after browsing the reviews and choosing the best product, don't forget to click on the buttons below to get the best deals on Amazon. nine0003

  • occupies an area of ​​5,000 square feet

    • 2. Information reports for weeds ready for spraying

    0019 5. Natria 100532524 Herbicide for combating grass and weeds

    Cons:

    Final take:

    This is undoubtedly one of the most effective weed killers you should try at home. He prevents and controls crabgrass before they germinate from seeds, and if others have already grown, he gets rid of them as well. What's more, it can kill or prevent crabgrass from invading your lawn up to 4 fields. It is a natural herbicide because it contains mesotrione as an active ingredient, which is naturally produced by bottle cleaning plants. The shell absorbs this herbicide through the shoots, roots, and leaves, altering the process of photosynthesis, slowing the growth of grass, and eventually killing the weed. This is the best crab grain killer if you want to prevent or control crab grain. nine0041

  • Has a ready-made applicator for easy application.
  • Effective on young and actively growing weeds.
  • Will only kill weeds, including grass, but will not kill your lawn.
  • Designed for northern lawns.
  • Can be used on grasses such as buffalo grass, Bermuda grass, Kentucky grass, ryegrass without damaging or killing them.
  • Daily use below 90 degrees Fahrenheit.

    • Cons:

    Final take:

    This is definitely a good spray to kill resistant crabgrass in your lawn. This is because it kills crabgrass even if there is sod in the lawn, and it does not kill or cause the lawn to change color. Like any other sprayer, you connect it to a garden hose and start using it when you turn on the water. Be sure to apply in spring and fall when the crabgrass is young and growing to get significant results. It also kills the roots; therefore, you don't have to worry about the grass growing back. nine0041

  • Handles up to 450 square feet.
  • Spray weeds until foliage is damp. This maximizes its effectiveness.
  • Has a ready-made applicator for faster application.
  • Kills weeds such as crabgrass, poison ivy and clover.
  • Can be used on driveways, steps, patios.

    • Cons:

    Final take:

    This is a non-selective herbicide that kills a wide range of weeds. Crab Grass Killer is organic and natural because it is weed resistant and does not harm the environment. It has an exclusive formula that kills crabgrass to the roots in a few minutes. This herbicide is easy to use as it has an applicator with which you spray it on weeds until the foliage is completely wet. It's important to make sure you cover the weed carefully for it to work effectively. If you need to treat individual weeds, apply the solution to the center of the plant. Repeat application to control new weeds from seed and re-emergence from perennials. This is a very effective and easy to use herbicide that you should consider. nine0003 Check Price

    recipe: noodles from crab sticks

    Home ›Salads and snacks› Cold and hot snacks

    Lapsha from crab sticks

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    6969696969 Reputation: +7541

    All author's recipes: 257

    Publication date: 2020-12-16

    Recipe liked: 21

    Ingredients:
    crab sticks - 200g;
    vegetable oil - 25 ml;
    paprika - 1ch;
    Provence herbs - 1ch;
    garlic - 2 cloves;
    dried parsley - 0. 5 tsp;
    lemon juice - 2 tbsp

    How to prepare :

    How delicious and easy to surprise guests? Make noodles from crab sticks!

    The recipe is very simple and will not take much of your time. nine0003

    You will need the crab sticks themselves, which will need to be unrolled. the ones I bought unfold easily without any problems, but if yours refuse to do this, then just dip them in hot water for a minute and they will unwind easily. Share in the comments what other sticks unfold without problems)

    So we unfold the sticks and stack them in a pile

    Cut into strips of 0.7-1 cm thick

    We put them on a plate, separate the strips from each other a little at this stage, then it will be more convenient to mix them.

    In oil, any vegetable, add paprika and aromatic herbs, I have a mixture of Provence herbs lemon halves

    Mix everything well and pour over the "crab noodles"

    Gently mix with 2 forks or chopsticks, close and leave for 10-12 hours in the refrigerator.

    Learn more