UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail:  dfculbert@ifas.ufl.edu

September  10, 2003 

Feature Article - for release the week of  September 15, 2003

Dan Culbert - Extension Horticulture Agent

 Recycling Nutrients & Fertilizer Fallacies

 Excessive phosphorus has been identified as a problem in Lake Okeechobee.  Fertilizers are one source of this nutrient pollution, and our landscapes can add to this problem.  Phosphorus finding its way into Lake Okeechobee is in part originating from our urban lawns, gardens and other public landscapes like golf courses and athletic fields.  The more we can do to minimize the use of excessive fertilizers from our environment, the better for the health of the lake.

I recently visited some of our local garden centers to see if low-phosphorus fertilizers could be purchased.  I had difficulty finding any - and many had high levels of the middle number that identify them as rich sources of phosphorus.  If you are concerned about the health of the lake, tell your garden store manager that you looking for low to no phosphate fertilizers, and they will start to appear in local stores. 

One way to reduce your need for purchased fertilizers is to recycle nutrients you already have.  Recycling not only reduces the amount of nutrients you import in purchased fertilizer, but keeps those nutrients in your Florida Yard and out of pond and canal water.  This runoff water in our area will ultimately run into the lake.

 So, what can the average homeowner do?

•  Leaving grass clippings on the lawn.  Research has shown this does not contribute to thatch and recycles the nutrients in the decaying clippings.  It also saves energy dollars and land fill space. And, you save effort and time needed to empty the clipping bag.

• Fallen leaves and small branches pruned from landscape plants make excellent mulch, which in turn decays and provide small amounts of nutrients.  Larger pieces of yard trash can be added to the compost pile, and returned to your Yard in time.  Yard waste is also a serious problem and expense for governments to handle.

• Compost improves sandy soils and provides slowly released nutrients.  It should be added to the entire planting zone when renewing garden beds, but not to individual planting holes.  Enriching planting holes with compost can create a “bucket” effect, where the soil holds too much water in the plant root zone too long.

• Fertilizer bags can be notoriously user-unfriendly.  Often you will need to read the fine print on the back of the bag or label to find out all the contents, their form and amounts.

It is important to calibrate you fertilizer spreader.  Often fertilizer companies recommend more nutrients than are necessary for a particular location. Our office can help show you how to make the adjustments needed to make the correct setting for your spreader. In our area, always choose a fertilizer low in phosphorus when purchasing for an established landscape!

There are also a few fertilizer fallacies out there:

Myth: All "organic" fertilizers are "slow release." Fact: Only those with water insoluble nitrogen or coated or chemically altered sources are slow release. 

Myth: Fertilizers are food for the plant. Fact: Fertilizers are plant nutrients  - plant food is what is produced in the leaves through photosynthesis using sunlight. 

Myth: Lots of fertilizer will produce more flowers, fruits and vegetables.  Fact: Excessive nitrogen causes lots of vegetative growth, which can reduce flowering and fruiting.

Myth: "Deep Root Feeding" by injecting fertilizer into the ground gets it right where the roots are. Fact: Most roots are in the top foot of soil, so deep injection just wastes the material. Surface application is best except on slopes where shallow injection is ok.

The University of Florida has several bulletins on Florida Yard fertilization and management, and I can refer you to some great websites on how to apply nutrients to you landscape in ways to help preserve the environment.  Contact our office if you would like additional information, or call or stop by our Okeechobee Extension office at 458 Hwy 98 North.  Our phone number is 863-763-6469, and you can email me at dfculbert@ifas.ufl.edu.

 The use of trade names is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them do not signify our approval to the exclusion of other products of suitable composition. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.