Good Riddance, Ragweed

Good Riddance, Ragweed

Good Riddance, Ragweed 

Ragweed isn’t just an eyesore in the home lawn—it can also cause quite severe allergic reactions with its pollen that may quickly bring an end to outdoor activities. Found throughout the United States, this broadleaf weed is easy to identify based on its hairy, fern-like leaves that are green and feathery in appearance. Ragweed is an annual weed, meaning it grows from seeds from the previous growing season and is capable of producing seed that will germinate the following year. In contrast, perennial weeds grow from established roots that last all winter.

Ragweed seed can begin to germinate as early as February if the soil warms and adequate moisture is available. It will continue to grow until the first frost of the season knocks it out. Ragweed begins to release pollen with cool nights and warmer days in August. This can last into the months of September and October. A single plant can produce thousands of seed and up to one billion pollen grains, making it an irritant when its pollen spreads on the wind in the late summer as the plant flowers. This weed thrives in soils that are dry and have poor fertility, typically where a strand of turfgrass is thin. Once established, this weed can easily outcompete other plants and quickly become an issue.

Cultural Control

Luckily, ragweed has its weaknesses and may be controlled effectively with cultural practices such as mowing, hand pulling weeds and proper lawn fertilization. When the weed is still young, it may be controlled effectively by weeding with the use of a hoe. However if the plant is already mature, it will leave behind roots that will regrow. Weeds should be pulled before they flower so that they are not able to spread seed or pollen and create new plants. Improving soil by implementing a proper fertilization plan can also help to give turfgrass a fighting chance and result in the production of a thick lawn, which can outcompete ragweed. A final cultural practice that homeowners can implement is regular mowing of the lawn. Continuous mowing will cause the ragweed plants to lose strength overtime and decline, which will also help to keep the weeds from flowering and producing seed.

Chemical Control

If cultural practices aren’t able to help get ragweed under control, there are also chemical options that can stop this problem before it overtakes your home lawn. The best time to apply a post-emergent to ragweed would be in the late spring or early summer, when the plants are still young but easy to identify. Check out some of our recommended pre- and post-emergent herbicide products for ragweed below.

These herbicides have the potential to suppress and control ragweed and other problematic weeds when applied correctly; however, it is essential to read the label carefully before making an application. This will help to ensure the product is compatible with your lawn and will not cause any damage.

  • Application Rate: 1.5–3 fl. oz. per 1,000 sq. ft.
  • Active Ingredient(s): Oryzalin 40.4%.
  • Ease of Use: Requires tank mixing and application with a sprayer.
  • Best Used On/For: Established warm season turfgrass before weeds appear.

  • Application Rate: 0.5 oz in 1–2 gallons of water per 1,000 sq. ft.
  • Active Ingredient(s): Halosulfuron-methyl 5.0%.
  • Ease of Use: Requires tank mixing and application with a sprayer.
  • Best Used On/For: Turfgrass, landscaped areas, residential, commercial, industrial sites and other non-crop areas.

Q4 Plus - 1 Quart

  • Application Rate: 1.8–3 oz. per 1,000 sq. ft.
  • Active Ingredient(s): Quinclorac 8.43%, Sulfentrazone 0.69%, 2,4-D, dimethylamine salt 11.81%, Dicamba, dimethylamine salt 1.49%.
  • Ease of Use: Requires tank mixing and application with a sprayer.
  • Best Used On/For: Established warm and cool season turfgrasses.

SpeedZone-herbicide

  • Application Rate: 0.75–1.8 fl. oz. per 1,000 sq. ft.
  • Active Ingredient(s): 2,4-D, 2-ethylhexyl ester 28.57%, Carfentrazone-ethyl 0.62%, Dicamba 1.71% and Mecoprop-P 5.88%.
  • Ease of Use: Requires tank mixing and application with sprayer.
  • Best Used On/For: Broadleaf control in established grasses. Product demonstrates superior cool season performance.

  • Application Rate: 0.75–1.8 fl. oz. per 1,000 sq. ft.
  • Active Ingredient(s): 2, 4-D, 2-ethylhexyl ester 10.49%, Mecoprop-p acid 2.66%, Dicamba acid 0.67%, Carfentrazone-ethyl 0.54%.
  • Ease of Use: Requires tank mixing and application with sprayer.
  • Best Used On/For: Broadleaf control in established grasses.

Please read the label carefully before applying to ensure that the chemical will not hurt your lawn.

As previously mentioned, a strong fertilization plan is ideal to help your lawn get healthier and outcompete weeds. Lawnifi is our recommended family of fertilizers. Check out our Fall Fertilizer Box to learn more.

To learn more about identifying what kind of weeds you may have in your lawn so that you know how to best remove them, check out our Identifying Common Lawn Weeds blog. You can also learn to differentiate between broadleaf weeds vs. grassy weeds in this blog.

For more information on weed control in general and the best ways to reduce weeds, visit our Weed Control blog.

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