1. Missed the live Ask the Expert event?
    Catch up on the conversation about fertilization strategies for success with the experts at Koch Turf & Ornamental in the Fertilizer Application forum.

    Dismiss Notice

When is the best time to apply post-emergent herbicide to a lawn???

Discussion in 'Pesticide & Herbicide Application' started by Vibe Ray, Feb 10, 2001.

  1. Vibe Ray

    Vibe Ray LawnSite Senior Member
    Messages: 785

    When is the best time to apply post-emergent herbicide to a lawn??? Are there any tips or tricks you know about applying them? Thanx
  2. HOMER

    HOMER LawnSite Gold Member
    Messages: 3,183

    After you see the weeds.
  3. Ocutter

    Ocutter LawnSite Senior Member
    Messages: 314

    Apply post during any time you see active weed growth. Look for the type of weed on he label b4 applying. Most labels tell you not to apply over 85 degrees so the lawn wont burn.
  4. Vibe Ray

    Vibe Ray LawnSite Senior Member
    Messages: 785

    know you were gonna say that, Homer???
  5. LoneStarLawn

    LoneStarLawn LawnSite Bronze Member
    Messages: 1,415

    I guess you knew the answer then already...
  6. Garry

    Garry LawnSite Member
    Messages: 184

    Keep in mind, the herbicide will best be absorbed and translocated throughout the plant during its period of early vegatative growth. Follow the label information. Your target pest is usually listed.
  7. Kent Lawns

    Kent Lawns LawnSite Senior Member
    from Midwest
    Messages: 870

    States require certification which requires you to know the answer before applying pesticides.

    Best time to apply is Fall. The weeds are translocating carbohydrate reserves into the root systems which makes them extremely vulnerable to and herbicide application. The waxy summer coating on the leaves is gone and many new weeds have germinated and are growing at this time.
  8. larrv45390

    larrv45390 LawnSite Member
    from Ohio
    Messages: 45

    The optimum time to control dandelions and other broadleaf weeds is in the fall and the second most effective time is in late spring, at or shortly after the flush of flowers. According to research, herbicide applications before mid-April will only "burn" the leaves and weeds will grow back by Summer. Herbicides containing 2,4-D, MCPP and dicamba are most effective for control of dandelions and other broadleaf weeds.

    Broadleaf weed herbicides are systemic and move through the plant in the phloem, which also transports photosynthate. The more areas of the plant that the herbicide translocates to, the more effective the kill. In the fall, perennial plants are "preparing" for winter, translocating photosynthate and storage products to the roots. If a herbicide is applied in the fall, it will translocate with the photosythate throughout the plant and to the roots, thus causing a complete kill. In the early spring on the other hand, the plant tends to be moving storage products from it's roots to reinitiate leaves and flowers. Thus a herbicide applied at this time will tend to remain in the leaves, not translocating to the roots, causing a burning of the leaves at best but usually not a complete kill.

  9. KirbysLawn

    KirbysLawn Millenium Member
    Messages: 3,485

    Just remember if applying to a newly seeded lawn it's best to have mowed the grass 4-5 times prior to the application of herbicides if possible.
  10. Mscotrid

    Mscotrid LawnSite Bronze Member
    from USA
    Messages: 1,456

    When is the best time to apply post-emergent weed control?

    Tuesday and Thursday between 9:00 and 10:30 am..

Share This Page