Don’t let soil be a dirty secret – get it tested


Should I fertilize? Should I lime? What does my garden need?

These questions often come from homeowners in Clay County, and the question warrants a simple response: “Have you had a soil test done?”

In fact, no fertilization or liming should be done without a soil test to let you know what is needed in the garden but luckily, your local UF/IFAS Clay County Extension Office is here to help. With tests available for pH as well as soil nutrients, we can help you make informed decisions before fertilizing which will help you save money, optimize growth and plant health, and protect the environment.

Why Test?

As many of your heard in the news last year or witnessed in Doctor’s Lake, Florida has an excess nutrient problem and some of that comes from excess fertilization of lawns and gardens. By knowing what your garden already has, you can make sure you are not adding to this issue by having extra nutrients flow into local waterways or down into our drinking water.

Also, not fertilizing at the proper rate or timing can lead to more plant disease, insect pests, and wasted money.

Testing your Soil

You have a few options to get your soil tested within the county with a range of results and costs.

First, we offer free soil pH testing to Clay County residents at the UF/IFAS Extension Clay County office. A sample should be an area of the yard with a specific use or crop such as landscape bed, vegetable garden, or lawn.

From your selected area, take small soil samples from 12-15 different spots. Soil should be collected from between 1-6” deep and mixed together in a small bag. In total, we only need around half-pint of soil for testing.

If possible, allow this sample to dry before bringing it into our office at:

2463 State Road 16 West, Green Cove Springs.

We will have a form available when you get there, and it usually takes between 5-10 business days to complete a sample. Wetter samples may take longer to test as we will need to dry it and we cannot accurately test highly organic soils such as potting mixes.

The University of Florida also offers soil testing, but with a cost of $3 for pH testing and $7 for soil pH and your major nutrients. With both tests you will get information on how much lime you may need for your garden, but the $7 test will give you nutrient and fertilizer recommendations as well. These samples are collected in a similar method to those for our pH testing program, but they must be mailed directly to the laboratory. We have forms and sample bags for these tests at our office, but information can also be found online at:

There are also private laboratories in the area to consider for these tests as well.

What do test results mean?

Soil pH test results will let you know how acidic or alkaline your soil is and what you need to do to correct it if needed. Liming is the main way to correct for a low pH but NEVER lime without first getting your soil tested.

Soil nutrient tests will let you know what is present in your soil and what should be applied to correct for any deficiencies. The test will help you determine how you need to fertilize, and I am here to help you with any questions you may have from those tests.

These tests will help to determine plant nutrition but will not be able to diagnose disease, insect issues, or contaminants and may not give a comprehensive answer as to why plants failed for the year.

If you have any more questions about soil tests, other landscape topics, or need plant or pest materials identified, contact the University of Florida/IFAS Extension Office online at, follow us on Facebook, or call by phone at (904)284-6355.


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