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

Dollar spots ?

Discussion in 'Pesticide & Herbicide Application' started by AWJ Services, Jul 12, 2005.

  1. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    I am in Georgia south of Atlanta and have noticed a large amount of yards with what appears too be dollar spots.Mostly in bermuda yards.
    I have 2 yards that are infected also .One has outside chemical application and one is fertilized by me.Both no irrigation in a month or so because of rain.
    The one I fertilized was done with John deere brand with iron added and I think 24 Nitrogen.
    Then the yard between these 2 lawns is not affected.I see it every where.
    I have hit my yard with heavy Nitrogen ,but since I am not licensed Fungicide is out.How long will it take for the Nitrogen too help?
    I called some chemical applicators and they say no one time application.Year long contract only.
    So what now?
  2. TurfProSTL

    TurfProSTL LawnSite Senior Member
    Messages: 693

    Fertilizing sometimes helps with Dollar Spot, but that isn't always the case. You don't need a license to treat your own lawn, so go buy a fungicide. A granular like Bayleton might be ideal, as you don't need special spray equipment - you apparently have a spreader.....
  3. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    Thanks for the Help.
  4. ThreeWide

    ThreeWide LawnSite Bronze Member
    Messages: 1,116

    Dollar Spot is usually triggered when Nitrogen availability is low, the top surface of the lawn stays wet (dew, humidity) and the soil below the surface is dry. This can be caused by a total lack of irrigation or simply not enough irrigation during periods of high humidity.

    Due to the excessive rainfall in GA this Summer, many are seeing DS as fertilizers are being leached out too soon by the rain. Normal fert schedules are not working this year. I can attest to that.

    Lawns on slopes are more prone to it, since the soil dries out faster. The best way to prevent it is to maintain good soil fertility and moisture with deep irrigation. Recently we had constant wet weather that was followed by a dry spell with cool mornings and heavy dew. This triggered DS everywhere unless people kept watering, which most didn't because it had rained so much previously. It only takes a few hot days for our soil to dry out in the first few inches, and that is where it matters.

    Sometimes a quick shot of Nitrogen will knock out DS, so you can try that first. If it doesn't improve in 10 days or so, a fungicide will be in order. Most fungicides will work well on DS.
  5. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    I have my books too take my test so I decided too look in them and get some info on Dollar spots.
    It really answered alot of questions as lined up with what Mr Turfunlimited posted.
    I feel the contributing factors were more lack of soil moisture,cool nights and low cutting heights.
    I hit the yard hard with Nitrogen and followed up a week later with some Fungicide.We will see what happens.
    Also what is the opinion on bagging and not mulching as far as the mulching helping too add Nitrogen.
  6. ThreeWide

    ThreeWide LawnSite Bronze Member
    Messages: 1,116

    You can search the site and find lots of details on bagging. I never do it because of labor, disposal, and the fact that you lose natural fertilizer.

    There is one instance where you might want to bag. When the lawn has a fungus, by mulching you might actually spread the disease. So if a lawn has DS, it would be a good idea to bag clippings until the problem has been cured.
  7. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    Makes sense.From what I understand dollar spot fungus does not produce spores so it can only be transmitted through contact.

    I bagged because of the look of the lawn.When I left there was usually nothing left on the lawn.The disposal was not a problem for me.I dumped on my on propertry and allowed to decompose for my own use.
  8. ThreeWide

    ThreeWide LawnSite Bronze Member
    Messages: 1,116

    I cut Bermuda on a 7-day rotation, and no clippings can be found after mowing. I use a mulching kit, and sometimes mow in two directions to make it really clean. Still much faster than bagging.

    To keep clippings to a minimum, Nitrogen management is critical. On these lawns, I use a 21-0-21 with 50% SCU and 50% UF (Nitroform).

    My point is that the key to easier mowing is controlling the growth rate.
  9. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    Sounds good too me.
    I still have alot too learn.
    One yard that has the Dollar spots is under a chemical application contract.
    The home owner is also Fertilizing .
    It is growing at an insane rate.
    Both of these yards are less than 2 years old.i wonder if young lawns are more prone too fungus.
  10. TMarch

    TMarch LawnSite Member
    Messages: 31

    Type of nitrogen is also important. I've seen some recent research showing ammonium sulfate 21-0-0 smoking the crap out of DS compared to other nitrogen sources. Plus the bermuda loves it.

Share This Page