For anything growing in the ground, soil is a very important thing. Soil gives plants a place to anchor their roots so they don’t fall over, holds water and nutrients for them to use, and supports a wide variety of living things that contribute to plant growth. Whether you want to grow a lawn, garden, or landscape bed, knowing a little about your soil can make a big difference in the quality of your plants!
There are a lot of terms that relate to soils. Some helpful ones to know include:
A chart of soil textures. Credit: Natural Resource Conservation Service
Soil particle sizes / soil texture. A soil that is composed of large particles is sandy, a soil with tiny particles is clayey, and a soil with mid-sized particles is silty. Multiple sizes of particles can mix together to form a soil, which is why you may see soils referred to with terms like, “sandy loam” or “silty clay loam”. This mixture of particle sizes gives a soil its texture.
Soil acidity / pH. The pH of a soil refers to its level of acidity. The pH scale ranges from 0 to 14. Low numbers mean the soil is acidic, while higher numbers mean it is basic, or alkaline. 7 is neutral, and many plants grow best in a slightly acidic soil (around 6.5). Some plants, like blueberries and azaleas, prefer a more strongly acidic soil (4.3-5.5). If the soil pH is too far from the plant’s preferred level, it may not be able to take up the nutrients it needs even if they are present in the soil. To raise the pH or make the soil less acidic, we can add garden lime; to lower the pH or make it more acidic, we can add sulfur (though this is not as long-term a solution).
Organic matter. All the living things out there die at some point, and when they do, other living things break them down as food. Fungi, bacteria, tiny insects, and more are all out there working to make sure you aren’t wading through piles of dead things. Instead, all that decomposed and partially decomposed plant (and animal) matter become part of the soil. Organic matter is part of a healthy soil, and helps it hold onto water and nutrients that plants can use.
Compost. When you make a pile of dead plant matter and help it decompose on purpose, you’ve made compost. By controlling the material you put into a compost pile as well as the amount of water and oxygen it gets, you can speed up the decomposition process and end up with organic matter to use in your garden.
Mulch. Mulch is any substance that sits on top of the soil. Wood chips, bark nuggets, pine straw, or even synthetic mulches like sheets of plastic are used to help keep weeds from growing and retain soil moisture.
Sandy soils can grow gardens, though they may need a little more attention!
To gather information about the soil, it can be a good idea to do a soil test. Your local Extension office can help you figure out how to do this. Once you do, you’ll receive information on your soil pH, what plant nutrients are in the soil, and recommendations on how much lime and fertilizer you’ll need to add for the year. Test your soil before you add any major amendments such as lime or fertilizer. This will help you add the right amounts at the right time – too much fertilizer, for example, can harm plants or run off into surrounding water bodies, causing environmental damage.
You can find more information on soil testing here, or visit your local Extension office. Soil tests can take up to two weeks to return a result, so plan ahead!
As you garden this fall, check out the North Florida Vegetable Gardening Guide, compiled by UF/IFAS Leon County Extension.
Getting into vegetable gardening, but don’t know where to start?
Even experienced gardeners know there’s always more to learn. To help both beginners and advanced gardeners find answers to their questions, the UF/IFAS Leon County Extension Office put together the North Florida Vegetable Gardening Guide. It incorporates multiple resources, including articles, planting calendars, photos, and UF/IFAS EDIS publications.
The North Florida Vegetable Gardening Guide covers the many aspects of vegetable gardening, including how to get started, site selection, insects and biodiversity in the garden, soil testing, composting, cover crops in the garden, irrigation, and more.
You can click here to view the digital version of the guidebook. We also have physical copies of the guide available at the UF/IFAS Leon County Extension Office (615 Paul Russell Rd., Tallahassee, FL 32301).
One big goal of establishing a home lawn and landscape is to enjoy an attractive setting for family and friends, while also helping manage healthy soils and plants. Soil compaction at these sites can cause multiple problems for quality plants establishment and growth. Soil is an incredibly important resource creating the foundation for plants and water absorption.
Photo courtesy: Stephen Greer, UF IFAS
Soils are composed of many different things, including minerals. In Florida, these minerals often include sand of differing sizes and clay in the northern area of the counties in the panhandle of Florida. Soil is also composed of organic matter, nutrients, microorganisms and others. When soil compacts, the air spaces between the sand or clay are compressed, reducing the space between the mineral particles. This can occur anytime during the landscape and lawn construction phase or during long term maintenance of the area with equipment that could include tractors, mowers, and trucks.
What can be done to reduce soil compaction? There are steps that can be taken to help reduce this serious situation. Make a plan on how to best approach a given land area with the equipment needed to accomplish the landscape of your dreams. Where should heavy equipment travel and how much impact they will have to the soils, trees, and other plants already existing and others to be planted? At times heavy plywood may be needed to distribute the tire weight load over a larger area, reducing soil compaction by a tire directly on the soil. Once the big equipment use is complete, look at ways to reduce the areas that were compacted. Incorporating organic matter such as compost, pine bark, mulch, and others by tilling the soil and mixing it with the existing soil can help. Anytime the soil provides improved air space, root will better grow and penetrate larger areas of the soil and plants will be healthier.
Even light foot traffic over the same area over and over will slowly compact soils. Take a look at golf course at the end of cart paths or during a tournament with people walking over the same areas. The grass is damaged from the leaves at the surface to the roots below. Plugging these areas or possibly tilling and reestablishing these sites to reduce the compacted soils may be necessary.
Photo courtesy: Stephen Greer, UF IFAS
Water absorption is another area to plan for, as heavy rains do occur in Florida. Having landscapes and lawns that are properly managed allow increased water infiltration into the soil is critically important. Water runoff from the site is reduced or at least slowed to allow the nutrient from fertilizers used for the plant to have more time to be absorbed into the soil and taken up by the plants. This reduces the opportunity for nitrogen, phosphorus, and other nutrients to enter water areas such as ponds, creeks, lagoons, rivers and bays. Even if you are miles from an open water source, movement of water runoff can enter ditches and work their way to these open water areas, ultimately impacting drinking water, wildlife, and unwanted aquatic plant growth.
Plan ahead and talk with experts that can help with developing a plan. Contact your local Extension office for assistance!
For all my years in the classroom, I never let students say the “d-word” when discussing soil science. In some instances, we had a “d-word” swear collection jar of a quarter when you used the term and even today, I hesitate from spelling the word out in text due to feedback from all those I have corrected. In case you still need a clue on the “d-word”, it ends in irt.
As a horticulturist for 46 years, I have read, heard, and been told many secrets to growing good plants. I still hold firm that without proper knowledge of how soil works, most of what we do is by chance. Soil is a living entity comprised of parent material (sand, silt, and clay), air, water, organic matter (OM), and microorganisms. It is this last item which makes our soils come to life. If you have pets, then you know they need shelter, warmth, air, water, and food. From this point forward think of soil microorganisms as the pets in your soil. If you take care of them, they will take care of your plants.
Sandy soil without any organic matter at the Wakulla County Extension office.
There is a huge difference in habitat from a sandy soil to a healthy soil with a good percentage of OM (5% – 10%). In one gram of healthy soil (the weight of one standard paper clip), you can have bacteria (100,000,000 to 1,000,000,000), actinomycetes (10,000,000 to 100,000,000), fungi (100,000 to 1,000,000), protozoa (10,000 to 100,000), algae (10,000 to 100,000), and nematodes (10 to 100) (1). A teaspoon of healthy soil can contain over four billion organisms (2). These microorganisms are part of the soil food web and they form a relationship between soil and your plants. They help convert nutrients to useable forms and assist with other plant functions.
The question becomes how to take care of your soil pets. For years we have performed practices that compromise these populations. Growing up we put all of our grass clippings in the weekly trash. We know now how valuable those clippings are and to leave them be. Two practices still common today though are tilling and raking leaves.
Master Gardener Volunteer vegetable bed with organic matter added.
Tilling has a limited purpose. If I place a layer of organic matter on top of the ground, then tilling incorporates the OM which feeds my pets. Excess tilling of soil introduces large amounts of oxygen which accelerates the breakdown of OM thus reducing our pet populations over time. Another adverse result from tilling is disturbing the soil structure (how the parent materials are arranged) which can reduce pore spaces thus limiting water percolation and root growth. There is a reason agriculture has adapted no-till practices.
Raking leaves (supposedly the sign of a well-kept yard) is removing large amounts of OM. Do you ever wonder why trees in a forest thrive? All of their leaves fall to the ground and are recycled by the microorganisms. Each of those leaves contains macronutrients (carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, sulfur, and magnesium) and micronutrients (boron, copper, chlorine, iron, manganese, molybdenum, nickel, and zinc) which are necessary for plant growth. You would be hard pressed to find all those nutrients in one fertilizer bag. So recycle (compost) your leaves versus having them removed from the property.
We are in our off season and tasks such as improving soil health should be considered now for soils to be ready in spring. Remember a little organic matter at a time and never work wet soils. As your OM levels build over the years, remember to change your watering and fertilizing schedules as the soil will be better adapted at holding water and nutrients. Soil tests are still recommended before fertilizing.
If you would like more tips on improving your soil, contact me or your local county horticulture extension agents. For a more in depth look at caring for your soils, read The Importance of Soil Health in Residential Landscapes by Sally Scalera MS, Dr. A.J. Reisinger and Dr. Mark Lusk (https://edis.ifas.ufl.edu/ss664).
Chapter 2: Soils, Water, and Plant Nutrients. Texas Master Gardener Training Manual.
The Importance of Soil Health in Residential Landscapes. 2019.
Daniel Leonard, Horticulture Agent at UF/IFAS Extension Calhoun County, answers commonly asked questions about raised bed gardening. In the video he discusses construction materials, the type of soil to use, fertilization, crop rotation, cover crops, and smaller container gardens.
