Common Ragweed

Description

Common ragweed is a summer annual weed that emerges early in the spring. It is often found in cultivated areas, but also occurs in roadsides and landscapes. It prefers heavy soils as opposed to sandy soils, and does not tolerate heavy mowing. The deeply dissected leaves are arranged oppositely when young, and alternately in older parts of the plant. Leaves are hairy on both surfaces. Ragweed produces copious amounts of pollen in the late summer, and often causes allergy problems.

Cultural Control

Maintain a dense, actively growing turf through proper mowing, fertilizing, and watering practices. Mow at the proper height for your selected adapted turfgrass. Coring and traffic control reduce compaction and encourage desirable turfgrass competition. It is best to control this summer annual broadleaf weed in late spring or early summer because it is easier to control at this time and the turf will have a greater chance of recovering the areas previously occupied by weeds.

Chemical Control

Herbicide and Formulation Amount of Formulation per 1,000 sq ft Amount of Formulation per Acre Pounds Active Ingredient per Acre
Preemergence and Postemergence Control
mesotrione, MOA 27 (4 SC) (Tenacity) 0.092 to 0.183 fl oz 4 to 8 fl oz 0.125 to 0.25
Precaution and Remarks: Use on residential turf, golf courses (not greens) and sod farms for pre- and postemergence weed control. Tolerant turfgrasses include St. Augustinegrass, centipedegrass, tall fescue, fine fescue, Kentucky bluegrass, and perennial ryegrass. Add a nonionic surfactant and repeat application after 2 to 3 weeks for improved postemergence control. Tank mix with prodiamine 65 WG for extended preemergence grassy weed control. Can be applied at seeding to all tolerant grasses except fine fescue. After turf germination, wait 4 weeks or until turf has been mowed twice before making a postemergence application. Also controls henbit, chickweed, dandelion, white clover, Florida betony, Florida pusley, ground ivy, oxalis, wild violet, creeping bentgrass, and yellow nutsedge.​
[sulfentrazone + prodiamine], MOA 14 + 3 (4 SC) (Echelon) 0.184 to 0.826 fl oz 0.5 to 2.25 pt 0.25 to 1.125
Precaution and Remarks: For use in residential and institutional lawns, athletic fields, sod farms, golf course fairways and roughs, roadsides, utility right-of-ways, railways, and industrial areas. Apply to turf following a second mowing if a good root system has been established. Apply up to 12 fluid ounces per acre to bentgrass at 0.5 inch or higher, fine fescue, and perennial ryegrass. Apply 18 to 24 fluid ounces per acre to perennial bluegrass, tall fescue, and all warm season grasses except St. Augustinegrass (do not apply) and bermudagrass (apply 18 to 36 fluid ounces per acre). For sod production, apply 6 months after establishment, and do not harvest within 3 months. Do not apply with adjuvants or surfactants. [Sulfentrazone + prodiamine should not be applied to cool-season turf with N-containing fertilizers unless some short-term discoloration is tolerable.​

Species Data

  • GROWTH SEASON / LIFE CYCLE
    • summer annual weed
  • GROWTH HABIT
  • LEAFLET NUMBER
  • LEAF MARGIN
    • lobed
  • LEAF HAIRS
    • upper / lower surface
  • LEAF / LEAFLET SHAPE
    • oval / egg-shaped / elliptical
  • LEAF WIDTH
    • 1 inch to greater than 2 inches
  • LEAF VENATION
    • pinnate
  • LEAF ARRANGEMENT
    • leaves are arranged oppositely when young, and alternately in older parts of the plant
      Figure 6
  • ROOT TYPE
    • taproot with many root hairs
  • FLOWER COLOR
    • inconspicuous
Common ragweed growth habit.Figure 1. Common ragweed growth habit.Common ragweed growth habit.Figure 2. Common Rragweed growth habit.Common ragweed growth habit.Figure 3. Common ragweed growth habit.Common ragweed leaflet number.Figure 4. Common ragweed leaflet number.Common ragweed leaflet number.Figure 5. Common ragweed leaflet number.Common ragweed leaf arrangement.Figure 6. Common ragweed leaf arrangement.