Soil testing is fundamental
By Ralph E. Mitchell
I have heard that one of our soil’s best attributes is for keeping plants upright – our Florida terra firma takes a great deal of ridicule! “Moon sand” or “beach sand” are common terms used to describe our local soil conditions. Did you know that Florida’s Official State Soil is called Myakka fine sand? While soils can vary from place to place, getting to know your soil through a soil test is a good first introduction into making improvements and successful gardening.
As a part of our world, soil is a combination of sand, silt, clay, organic matter, water and air. Soils can be sandy, clayey, loamy, or even muck which are soils high in organic matter. Our local soils tend to be sandy, but we often label them as a group called “residential fill” soils. This soil has been trucked in to raise the base of the building site before house construction begins. As such, this fill can be good, bad or indifferent. In most cases, the soil is not the best and does not have the characteristics of soils found in undisturbed and rural areas. But we have to do the best with what we have and this is an achievable goal.
A soil test conducted by the University of Florida/IFAS Soil Lab is a good starting point to find out your soil baseline. This test will result in finding out the pH of the soil – is it acid or alkaline, and what are the levels of Phosphorus, Potassium, Calcium, and Magnesium. Nitrogen cannot be tested in this case as it is a nutrient that is very mobile in the soil and an accurate reading could only be obtained with a tissue test. The basic nutrient levels will give you an accurate measure of what is present, and the pH will indicate what types of plants may do best there and which nutrients may be available or unavailable to the plants.
You can either come to our office and obtain a soil test form and specimen bag, or simply download the form yourself from http://edis.ifas.ufl.edu/pdffiles/SS/SS18700.pdf . This will provide the “LANDSCAPE & VEGETABLE GARDEN TEST FORM”. This form has instructions on taking the sample and how to prepare it. Generally, secure a small amount of soil from 10 to 15 different spots (subsamples) in the area you want to test so that, when mixed together, it adds up to a minimum of one-half pint – this is your composite sample. For a lawn, take the soil from the upper two to four inches, for a vegetable garden or landscape plants, take a sample from the upper six inches. Spread the soil on clean paper or other suitable material and air dry if moist. Once dry, you can use a zip lock baggie for the sample. Complete the form and enclose a check for the correct amount send it to Gainesville in your own shipping box. Within two weeks you will get the results returned, and we get a copy in case you need any help with interpretations.
The results will help you determine what types of fertilizers you might need, what types of plants might best grow in your yard, and what improvements might be strategized to make your landscape more sustainable. Somethings like dealing with very high pH is difficult, if not impossible to permanently change. As such, this information helps you determine which plants are best adapted to your site. For example, plants that are what are called “acid-loving” such as blueberries or Ixora, will not do well in soil that has been determined to be highly alkaline. This can save you time, money and frustration. One of the principles of Florida-Friendly Landscaping™ is “Right Plant, Right Place”. These are words well spoken.
Without soil testing, you may be blindly stepping into unknown territory. Soil testing is one tool that can begin the conversation towards a beautiful and fruitful landscape! For more information on all types of gardening topics, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.
http://edis.ifas.ufl.edu/pdffiles/SS/SS18700.pdf – LANDSCAPE & VEGETABLE GARDEN TEST FORM. The University of Florida Extension Service, IFAS.
Mylavarapu R. S. (2016) Soil Sampling and Testing for the Home Landscape or Vegetable Garden. The University of Florida Extension Service, IFAS.
Mylavarapu, R. & Wiese, C. (2011) Soil pH and the Home Landscape or Garden. The University of Florida Extension Service, IFAS.