K-State Research and Extension Horticulture Newsletter
  • Newsletters
  • About
  • Contact
  • Pest of the Week

Crabgrass Control

7/31/2017

1 Comment

 
Picture
This is the time of year when people really notice crabgrass infestations. By far the best way to control crabgrass is to prevent it by maintaining a good, thick lawn. Crabgrass is an annual that must come up from seed each year and the seed must have light in order to germinate. If a lawn is thick enough that sunlight does not reach the soil, the crabgrass will not germinate. Under Kansas conditions it is not easy to maintain such a lawn; so many gardeners do the next best thing and apply a crabgrass preventer in the spring. 


Crabgrass preventers kill the seed as it germinates. Most do not have any effect on crabgrass that has already come up. If we are too late to apply a preventer, we do have other herbicides that will kill crabgrass after it is up including Ortho Weed-B-Gon Max + Crabgrass Control, Bayer All-in-One Lawn Weed and Crabgrass Killer and Fertilome Weed Out with Crabgrass Killer. Each contains quinclorac, which is a crabgrass herbicide, as well as other active ingredients that control broadleaf weeds.  Quiclorac is an excellent crabgrass killer that controls not only crabgrass but also has good activity on foxtail and certain broadleaves such as field bindweed, black medic and clover. However, it does little to nothing to goosegrass.  However, quinclorac can harm garden plants if clippings are used as mulch.  Clippings should be returned to the lawn or discarded.  Even composting will not break down the quinclorac.

​Fortunately, crabgrass starts declining about the middle of August. This is about the same time that cool- season grasses such as tall fescue and Kentucky bluegrass start to come out of their summer doldrums. By the first of September, the crabgrass will be less noticeable. Therefore, a small infestation is best ignored. Remember that crabgrass is a warm-season annual and will be killed by the first frost. (Ward Upham)

1 Comment

Turfgrass: Proper Timing for Crabgrass Preventers

3/27/2017

0 Comments

 
Picture
Crabgrass preventers are another name for preemergence herbicides that prevent crabgrass seeds from developing into mature plants. Many people have a somewhat foggy idea of how they work and assume they kill the weed seed. Such is not the case. They do not kill the seed or even keep the seed from germinating but rather kill the young plant after it germinates.  Therefore, they do not prevent germination but prevent emergence.

Crabgrass preventers are just that – preventers. With few exceptions they have no effect on existing crabgrass plants, so they must be applied before germination. Additionally, preventers do not last forever once applied to the soil.
 
Microorganisms and natural processes begin to gradually break them down soon after they are applied. If some products are applied too early, they may have lost much of their strength by the time they are needed. Most crabgrass preventers are fairly ineffective after about 60 days, but there is considerable variation among products. (Dimension and Barricade last longer. See below.)
 
For most of Kansas, crabgrass typically begins to germinate around May 1 or a little later. April 15 is normally a good target date for applying preventer because it gives active ingredients time to evenly disperse in the soil before crabgrass germination starts. However, this year, we may want to go a week or two early.  For southeast Kansas, this week would be appropriate, and for northwest Kansas, mid-April would be best.
 
Even better, base timing on the bloom of ornamental plants. The Eastern Redbud tree is a good choice for this purpose. When the trees in your area approach full bloom, apply crabgrass preventer. A follow-up application will be needed about 8 weeks later unless you are using Dimension or Barricade. Products that do require a follow-up application include pendimethalin (Scotts Halts) and Team (Hi-Yield Crabgrass Control).
 
Dimension and Barricade are the only two products that give season-long control of crabgrass from a single application. In fact, they can be applied much earlier than April 15 and still have sufficient residual strength to last the season. Barricade can even be applied in the fall for crabgrass control the next season.
 
Dimension can be applied as early as March 1. Because of the added flexibility in timing, these products are favorites of lawn care companies who have many customers to service in the spring. Though Dimension is usually not applied as early as Barricade, it is the herbicide of choice if it must be applied later than recommended. It is the exception to the rule that preemergence herbicides do not kill existing weeds. Dimension can kill crabgrass as long as it is young (two- to three-leaf stage). Dimension is also the best choice if treating a lawn that was planted late last fall. Normally a preemergence herbicide is not recommended unless the lawn has been mowed two to four times. But Dimension is kind to young tall fescue, perennial ryegrass, and Kentucky bluegrass seedlings and some formulations can be applied as early as two weeks after the first sign of germination. However, read the label of the specific product you wish to use to ensure that this use is allowed. Lawns established in the fall can be safely treated with Dimension the following spring even if they have not been mowed.
 
Note that products containing Dimension and Barricade may use the common name rather than the trade name. The common chemical name for Dimension is dithiopyr and for Barricade is prodiamine. Remember, when using any pesticide, read the label and follow instructions carefully.

We recommend crabgrass preventers be applied before fertilizer so that the grass isn’t encouraged to put on too much growth too early. However, it may be difficult to find products that contain preemergents without fertilizer. Those that don’t contain fertilizer are listed below. I didn’t find any products containing Barricade that did not also have a fertilizer. If anyone knows of other products that should be listed, let us know and we will publish them in a later newsletter.
 
Pendimethalin
- Scotts Halts
Team (Benefin + Trifluralin)
- Hi-Yield Crabgrass Control
Dimension
- Hi-Yield Turf & Ornamental Weed and Grass Stopper
- Bonide Crabgrass & Weed Preventer
- Green Light Crabgrass Preventer
(Ward Upham)

0 Comments

    Authors

    Ward Upham runs the Horticulture Response Center in the Department of Horticulture and Natural Resources at Kansas State University. Other contributors include K-State Extension Specialists.

    RSS Feed

      Subscribe to the newsletter by entering your e-mail and clicking the link below

    Subscribe

    Archives

    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014

    Categories

    All
    All America Selections
    All-America Selections
    Amaryllis
    Anthracnose
    Ants
    Aphids
    Apples
    Apricots
    Army-cutworm-moths
    Ash-borer
    Ashes-in-the-garden
    Asparagus
    Bacterial-wilt
    Bagworms
    Bark-shedding
    Beans
    Bermudagrass
    Bird-feeding
    Bitter-cucumber
    Blackberries
    Blackspot
    Black-walnuts
    Blister Beetles
    Blossom End Rot
    Blossom-End Rot
    Blueberries
    Botryosphaeria
    Breaking-dormancy-early
    Breaking-dormancy-early
    Bristly Rose Slug
    Broccoli
    Brownheaded-ash-sawfly
    Brown-patch-on-fescue
    Brown-rot-of-fruit
    Budworms
    Buffalograss
    Bulbs
    Bulb Storage
    Butterflies
    Butterfly Gardening
    Cabbage
    Cabbage Worms
    Caddo Sugar Maples
    Calcareous
    Cantaloupe
    Carpenter Bees
    Cauliflower
    Cedar Apple Rust
    Cherry Leaf Spot
    Chickweed
    Chiggers
    Christmas Cacti
    Christmas Trees
    Cicada
    Cicada Killer Wasps
    Codling Moth Control
    Cold Frames
    Cole Crops
    Colorado Potato Beetle
    Columnar Trees
    Compost
    Conservation Trees
    Container Gardening
    Controlling Volunteer Trees
    Cool Season Vegetables
    Cool-Season Vegetables
    Core Aeration
    Corn Earworm
    Corn Gluten Meal
    Crabapples
    Crabgrass Control
    Crickets
    Crop Rotation
    Cucumber
    Cucumber Beetles
    Daylilies
    Deadheading Flowers
    Dormant-seeding-turfgrass
    Dothistroma Needle Blight
    Drip-irrigation
    Dr-seuss-gardening
    Dutch-elm-disease
    Early Blight
    Eggplant
    Elm Flea Weevil
    Elm Leaf Beetle
    Elm Pocket Gall
    Emerald Ash Borer
    Euonymus Scale
    European Pine Sawfly
    Excessive Rain
    Fall Armyworms
    Fall Colors
    Fall Gardening
    Fall Lawn Seeding
    Fall-webworm
    Family-heritage-gardening
    Fertilizing-cole-crops
    Fertilizing-flowers
    Fertilizing Lawns
    Field-bindweed
    Field Dodder
    Firewood
    Flatid Planthoppers
    Flooding
    Floral Arrangement Care
    Flourescent Lights
    Flowerbed Design
    Flowering
    Frost On Lawns
    Fruit
    Fruit Baskets
    Fruit Damage From Cold
    Fruit Trees
    Fungus Gnats
    Galls
    Garden Hoses
    Gardening Calendar
    Garden Seed
    Garden Spiders
    Garden Tool Care
    Garlic
    Goldenrod Soldier Beetle
    Grapes
    Grasshoppers
    Grass Seed
    Green June Beetles
    Growing Cuttings Inside
    Grubs
    Hackberry Caterpillar Butterflies
    Hackberry Psyllids
    Hardiness
    Harlequin Bug
    Harvesting
    Help For New Gardeners
    Henbit
    Herbicide Damage
    High PH Soils
    Holly
    Hollyhock
    Honeysuckle
    Hornworms
    Horseradish
    Houseplants
    Hydrangea
    Ice Melters
    Invasive Plants
    Iris
    Iron Chlorosis
    Irrigation
    Itch Mites
    Japanese Beetles
    Junipers
    Kansas Garden Guide
    Kentucky Bluegrass
    Knotweed
    Lacebugs
    Ladybird Beetles
    Landscape Design
    Lawn
    Lawn Calendar For Cool Season Grass
    Lawn Calendar For Cool-Season Grass
    Lawn Calendar For Warm Season Grass
    Lawnmower Care
    Lawn Seeding
    Leaf Scorch
    Leaves
    Lettuce
    Lilac
    Lilac Borers
    Little Barley
    Marcescence
    Maximizing Garden Space
    Melons
    Millipedes
    Mimosa Webworm
    Mole Control
    Mouse Damage
    Mowing
    Mulch
    Mums
    Mushrooms
    Mycosphaerella Leaf Spot
    Nantucket Pine Tip Moth
    Native Prairie Flowers
    Needle Drop On Conifers
    New Gardener Resources
    Nightcrawlers
    Nuts
    Oak
    Oak Leaf Itch Mite
    Onions
    Orchids
    Organic Matter
    Organic Sources Of Nitrogen
    Ornamental Grass
    Overseeding Lawns
    Overwintering Geraniums
    Paperwhite Bulbs
    Pawpaw Trees
    Peaches
    Pears
    Peas
    Peonies
    Peony
    Peppers
    Perennial Garden Clean Up
    Perennial Garden Clean-up
    Pesticide Effectiveness
    Pine Wilt
    Planting Calendar
    Plastic Mulch
    Plum
    Poinsettia
    Poison Ivy
    Poisonous Plants
    Pokeweed
    Poor Drainage
    Potatoes
    Powdery Mildew
    Powdery Mildew On Lawn
    Power Raking
    Propagating-woody-plants
    Prop Up Fruit Limbs
    Pruning
    Publications
    Quince
    Rabbits
    Raccoons
    Rain-barrels
    Raspberries
    Recommended-plants-for-ks
    Rhubarb
    Roasting Pumpkin Seeds
    Roots
    Rose
    Rose Rosette
    Roundup For Lawns
    Salad Garden
    Sawfly Larvae
    Scale
    Scale Insects
    Screen Trees
    Sedum
    Seed Germination
    Seed Germination
    Seed Tape
    Septoria Leaf Spot
    Shrub Pruning
    Shrubs
    Sidedressing
    Slime Molds
    Slugs
    Smut
    Soil
    Soil Preparation
    Soil Temperature
    Spider Mites
    Spiders
    Spirea Aphid
    Spittlebugs
    Spray Water PH
    Spreaders
    Spring Bulbs
    Spring Flowering Shrubs
    Squash
    Squash Bugs
    Squash Vine Borer
    Squirrel Damage
    Starting Seed
    Stink Bugs
    Storing Power Equipment
    Storm Damage
    Stratification
    Straw-bale-gardening
    Strawberries
    Succession Planting Of Vegetables
    Sunflowers
    Sunscald
    Survey
    Sweet Corn
    Sweet Potatoes
    Tall Fescue
    Tan/White Drupelets
    Termites
    Thatch Control
    Ticks
    Tomatoes
    Transplant Fertilization
    Tree Health
    Tree Leaves And Turf
    Tree Planting
    Trees
    Tubakia
    Tubakia-leaf-spot
    Turf-in-shade
    Twig-girdlers
    Vegetable-flowersfruit
    Vegetables
    Vegetable Seed
    Vegetable Transplants
    Velvet Ants
    Vinegar As Herbicide
    Walnut Caterpillars
    Warm Fall
    Water Damage
    Watering
    Watermelon
    Water Teepees
    Weeds In Flower Beds
    Weeds In Turf
    Weird Squash
    White Grubs
    Whitelined-sphinx-caterpillar
    Wildflower Establishment
    Wildflower-establishment
    Wildlife
    Wild Violet Control
    Wind Chill
    Winter Damage
    Winterizing Water Lines
    Winter Mulching Vegetables
    Winter Squash
    Wood Chips
    Worms From Oaks
    Yellowjackets
    Yellow Nutsedge

Powered by Create your own unique website with customizable templates.