Defending the practice of fertilizing our lawns, plants

Representatives from DEP, IFAS and Department of Agriculture agree that most of these fertilizer ordinances are not science based and actually have contrary results due to decline of plant material which results in greater nutrient movement as run off and leachate. Getty Images

I feel the need to defend the practice of fertilizing our lawns and plants. Healthy plants with healthy and extensive root systems are the best defense against all pollutants not just fertilizer. They are the filtration system for the earth. They absorb some nasty pollutants and use them throughout the plant rendering them harmless to the environment. 

One editorialist wrote that the horticulturalists were only thinking about the health of their plants and not the environment. That is exactly the point. The two go hand in hand!

First of all, I am not anti-fertilizer ordinance. I have been touting environmental horticultural practices since before it was popular. I am, however, very much against these more stringent ordinances like the one adopted on Marco Island as they do more harm than good. The Conservancy and Sierra Club would have you believe that the more stringent fertilizer ordinances they are pushing are better for the environment but this is not true. With all due respect they do not have the credentials of the people who oppose them.

Representatives from DEP, IFAS and Department of Agriculture agree that most of these ordinances are not science based and actually have contrary results due to decline of plant material which results in greater nutrient movement as run off and leachate. Those were Laurie Trenholm’s words.

Representatives from DEP, IFAS and Department of Agriculture agree that most of these fertilizer ordinances are not science based and actually have contrary results due to decline of plant material which results in greater nutrient movement as run off and leachate. Getty Images

There are 177 cities in Florida and only a handful around you have these harmful ordinances. The map the Conservancy presented to us with the red outline of areas with nutrient overload did not even surround Marco Island. It is an area to the north which is overloaded due to the clogged mangrove culverts on 92 and the die off area.

I begged our city to adopt the state model for the Marco Island ordinance since it does protect the environment, exactly because it was written with input from the experts who know the facts. I found it very sad and a bit telling that Laurie Trenholm told me in an email that she “can only attend these hearings if requested to do so by a council member or staff to present data. I have not been approached by any of them on this meeting. I’m sure the Sierra Club will be represented however.” 

I did ask our City Council to reach out to her. Marco Island can still stand out as a model community, willing to do the smart thing by adopting the state model ordinance. These more restrictive ordinances should be banned since they are not backed by science which is required by the state statute.

I have some specifics of the ordinance I would like to point out.

Prohibitedperiod

  • Statemodel – Storm, flood watches and saturated soil.
  • Marco Model – Line 253, prohibited period from June 1 to Sept 30.
  • Notes: Study by Laurie Trenholm, soluble urea applied in spring (April-May); early summer (June-July); late summer (August- September); and fall (October-November). Rates of 1, 4, 7 or 10 lbs. per 1,000 sq. ft. were all used.

St. Augustine grass was in good health, active growth and cover. The dense and active root and shoot system allowed the grass the ability to take up and use the nitrogen even at excessively high rates. Nitrate leached did not exceed 1.4% and was generally below 1%.

One of the most important principals of fertilizer timing is avoiding fertilizer application to dormant plants. During dormancy plants take up very small quantities of nutrients and applied nutrients are more likely to leach or run off.  Our lawns are more likely to be semi-dormant or dormant during the winter months.

Restricting fertilizer applications to October – May means a majority of fertilizer applications will happen in the cold/dry dormant months when more nutrients are likely to leach.  People who don’t know the science will think fertilizing then is a good thing to do.  Rather than educating people on proper fertilizer techniques we are sending the wrong message.  The better way is to teach them not to fertilize when heavy rains are expected and, as important, not to fertilize when it is cold/dry.  You cannot put a date on proper fertilizer timing.

Content and application rate

  • Statemodel Label requirements 5E-1.003; Florida Administrative Code and IFAS landscape recommendations. All written by experts in the turfgrass field and backed by scientific studies.
  • Marcomodel – Line 262 to 264.

At least 50% slow-release nitrogen.

Laurie Trenholm’s study found no differences in nitrate leaching from either soluble or slow release sources when applied to actively growing, healthy turfgrass. Healthy turf is able to take up the fertilizer that is applied to it, as long as the fertilizer is properly applied. In fact, some slow-release nitrogen fertilizers do not react if the soil is cold and/or dry which means they should not be applied in our cold, dry winter months since they will be more likely to leach or run off. Thus the 50% rule means that a lot of fertilizer will not be properly applied resulting in increased leaching and run off.

Fertilizer free zone

  • State model – A buffer of 10 feet on water bodies and wetlands or 3 feet with a deflector shield to prevent fertilizer in the water.  Also list a voluntary low maintenance area of 6 ft. This allows for fertilizing our Marco Island back yards using a deflector shield.  We also have to consider all of our shrubs and trees. 
  • Marco model- Line 245 to 247, a buffer of 10 feet with no fertilizer around water bodies.

This does not allow for the fertilization of most Marco Island back yards at all. With no fertilizer these turfgrass areas and shrubs and trees will begin to decline and eventually die. And as noted earlier, the best line of defense for prevention of leaching is a healthy and actively growing root system. 

The loss of root systems behind Marco Island homes will mean any pollutants from the property will leach right into the canal behind it. Use of a deflector shield will allow for fertilizing without putting fertilizer into the water.

Also, loss of property values as the esthetics begin to decline. Are you allowed to dictate to people that they cannot maintain their properties? This is excessive overreach of government.

Exemptions  

  • Statemodel – Agriculture
  • Marcomodel – Line 230 to 233, newly planted turf and/or landscape plants may be fertilized for a 60-day period beginning 30 days after planting.

As per Laurie Trenholm, newly planted turf, whether sodded, seeded, sprigged or plugged should not be fertilized with nitrogen for at least 30 to 60 days after planting due to the potential for large nutrient leaching before a root system has been established.  This is now recommended as a best management practice!

In summary, the discharges from our storm water drains emptying directly into our canals all around Marco Island put a lot more nitrogen into the water from all the parking lots and roads than leached fertilizer from our landscapes.  And now we have a misinformed ordinance that causes more leaching than ever before. The latest reports show a decline in water quality in our canals.  How about you leave us alone and educate yourselves on the science and get to the real root of the problem.  It’s a lot more complicated than our fertilizer.  And no one should want to live in a world without plants!

More:Gardening: Your ‘do to’ list after a storm

And:Gardening: Evaporation and transpiration – Irrigation important for plant health

Also:Gardening: Lawn disease and balancing your water needs

Peter and Eileen Ward have sold Greensward of Marco after 40 years in the lawn and landscape business on Marco Island. You can reach Eileen with comments or questions on her columns via email at Gswdmarco@comcast.net or call 239-269-0192.