How Long To Wait After Fertilizer Application?

Discussion in 'Homeowner Assistance Forum' started by Nullqwerty, Aug 20, 2013.

  1. Nullqwerty

    Nullqwerty LawnSite Member
    Messages: 37

    Hey folks,

    I've been trying to research the safety of fertilizer application and children playing in a treated lawn. Harder than I thought.

    I know I can use organic fertilizer if I wanted to be ultra-safe. But lets put that aside. Assuming I'm using normal non-organic fertilizer, is there a general consensus as to how long after an application it becomes safe for children to play in the grass? Is it considered safe again after 24 hours or 48 hours or 1 week? Or is the idea that a lawn regularly/scheduled treated is never safe for children to regularly play in?

    I am fine with saying to my kids "Don't play on the grass for the next 2 days" and am very confident it won't be a problem. It is a problem if I say though "The grass is never safe to play in kids". In that case, I'll go organic.

  2. FdLLawnMan

    FdLLawnMan LawnSite Bronze Member
    Messages: 1,253

    There is no restriction as to when people can enter an area treated with straight fertilizer. You are talking about nitrogen, phosphorous and potash. What is unsafe about those materials. Personally I think they are safer than dried human or cow waste.
  3. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,126

    I remember a daycare center specifically prohibiting "organic" fertilizers because of the possible pathogens and parasites present. Fertilizer watered in is not harmful to children or pets once the irrigation is dry. Chemical N, P and K is no more harmful than table salt. People do swim in the ocean, right?
  4. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,160

    If the fertilizer contains pesticides, the label will provide the time of safe re-entry. For instance;

    Precautions And Restrictions:
    Do not apply this product in a way that will contact any person or pet, either directly or through drift. Keep people and pets out
    of the area during application. Do not allow people or pets to enter the treated area until dusts have settled.
  5. americanlawn

    americanlawn LawnSite Fanatic
    from midwest
    Messages: 5,955

    Organic... a general term. Natural? Synthetic organic? How synthetic? Any more, most companies that sell "natural" organic fertilizer synthetically modify their products.

    "Natural" organic fert can contain dangerous pathogens, contaminants and hazardous dust particles.

    Manure runoff often causes many lakes & rivers "off limits" for swimmers.

    We stopped offering "natural fertilizers" some years back because we were concerned about health issues. We prefer to use professional products designed to be used in the green industry. Too many folks have children, grandchildren, dogs, cats, etc. Customers also prefer non smelling products.

    We offered natural organic fert on a trial basis. Now we use clean products that work, don't smell, don't contaminate, and homeowners can walk on their lawn immediately (granular) or when it dries (liquid).

    my 2 cents after 35 years

    p.s. The day care centers who are customers also prefer non-organic because they have googled (after my recommendation)
    Last edited: Aug 20, 2013
  6. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,126

    You know which "organic" I mean. A long time ago, I mentioned that making a client's property look or smell like a water treatment plant, stable or barnyard was not how I worked anyway. Only exception to that rule is kelp emulsion or the non pathogenic liquid biostimulants. BTW Milorganite is not legal in Hawaii. Too many heavy metals. C&C as well as many golf courses do spread sewage solids, then get the complaints.

    It does not make economic sense for me either. I am not in the business of making compost. Any time I want to use it, I have to buy it. Get lots of broadleaf weeds free in that stuff as part of the bargain. On the other hand, I use clean liquid mixes that cost $5 or less per 1000. Reference that to the fact that any fertilizer starts at around $25 a bag, something containing coated urea is anywhere from $35-60 per bag.
  7. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I've never heard of compost being carcinogenic...
    another aspect being ignored in this discussion is building up the SOM, CEC, absorption/retention, microbes and soil structure in general...
    Soil structure is very important to all plants and is a key environmental factor the determines the health and well-being of the turf... Synferts, add nothing to the structure of the soil...
  8. foreplease

    foreplease LawnSite Silver Member
    Messages: 2,062

    I agree with evry post here except Samallaxe's, which was way far off topic anyway.

    Greendoctor, Milorganite fixed that problem here. They changed the label ha ha.

    Some schools here have been bullied into using "organics." Turned out only about 1/4 of N was from organic source - and that was composted chicken manure. How would you like to get tackled face down in that? Many cases of chronic lung disease are attributable to poultry manure.

    I get this question several times a year and I don't even work with homeowners. Usually it is to settle a disagreement between spouses. In Michigan we cannot use the word "safe" in any context with regard to pesticide applications but I have no hesitation in sending a team out to practice or play on a field that was fertilized yesterday or even the same day if they are not routinely tackling each other. In my view, the risk to the grass by letting them back on is greater than the risk to the kids.
  9. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    Come now GD. One has to merely pull a couple of MSDS's to demonstrate this is not true.
  10. andyslawncare

    andyslawncare LawnSite Senior Member
    Messages: 812

    it isn't safe for kids to eat grass or leaves, and its bad parenting if they do that. Otherwise if you arent using other spray chemicals you should be ok. I tell my customers to wait until dry after a spray and the same thing is on the pesticide signs I even write the time and date and note liquid or dry of application on signs where I know they have dogs or kids. Placing a sign at the time of application takes it out of your responsibility. Its like slipping in a store with a sign stating 'wet floor' over the area of a wet floor.

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