What’s in your soil?
As many of us transplants can attest, the “soil” in most Southwest Florida residential areas is very different from elsewhere.
Unlike the nutrient-rich, microbe-laden soils found in many other regions of the country, a great deal of the soil here in Southwest Florida is devoid of many of the important nutrients plants need in order to make their own food via photosynthesis. Instead, what passes for soil in residential landscapes is a combination of bedrock “fill” material high in phosphorus and calcium but little else, supplemented by sand, which provides nothing by way of nutrition. It is that fill of crushed limestone material which often contributes to a pH soil reading that can lean quite a bit on the alkaline side.
You can check for pH and nutrient content by getting your soil tested. There are a variety of at home pH test products, which are readily available for purchase online, or you can save yourself some money and visit the Lee County Extension Office in Fort Myers (or your local county Extension Office if in another county) for a free pH soil test. Gather soil samplings in various landscape locations, digging down 3-6 inches, and drop off during business hours. Hours are posted at http://sfyl.ifas.ufl.edu/lee/.
To test for nutrients, soil samples can be mailed to the Soils Testing Laboratory in Gainesville, FL. Visit https://soilslab.ifas.ufl.edu/ for further information.
Why is understanding whether your soil pH tilts acidic, alkaline or hovers at neutral and what nutrients are currently available in the soil so important? The reason is because different landscape plants have different soil pH levels and nutrient requirements. Make sure to do your research!
As the Dutch philosopher Erasmus noted, “Prevention is better than cure.” Therefore, the steps you take during landscape design and in plant selection will increase the chances of having a healthy landscape.
You can begin by checking out The Florida Friendly Landscaping Guide to Plant Selection & Landscape Design at https://ffl.ifas.ufl.edu/resources/publications. This publication provides an array of useful information relating to the requirements of a variety of trees, shrubs, perennials, and other vegetation.
If you choose your landscape plants unwisely, you can easily end up with the wrong plant in the wrong place. Some vegetation, such as Jatropha, Frangipani, Bulbine and Croton, thrive in almost any type soil pH while others, such as Purple Coneflower, Muhly Grass, Simpson’s Stopper, and Florida Privet prefer alkaline. Yet others, such as Ixoras, Coreopsis, Hibiscus, Gardenia and some ferns prefer acidic soil. If pH is not suited to the plant, the plant may be unable to effectively access nutrients, thus weakening the plant. Without intervention from the homeowner to “fix” issues that arise, a further downturn is more than likely.
If your soil is on the acidic side, you can raise the pH level temporarily with elemental sulfur, but it is important to apply according to label directions, taking care to avoid applying too much, thereby burning your plants. Again, going this route provides only short-term relief. A better approach would be to select plants suited to landscape conditions. As an offset to poor nutrient content, working organic material such as compost into the soil during landscape prep will benefit soil structure plus add small amounts of macro and micro-nutrients, along with beneficial microbes. Fertilizing appropriately in the aftermath of planting can add important nutrients that may be lacking. Before purchase, keep in mind that various plants are naturally prone to nutrient deficiencies, e.g., Foxtail palm and ornamentals such as Hibiscus. While both examples are lovely to observe, recognize that added TLC may be needed to mitigate those natural tendencies.
Janetta Fox is a Lee County Master Gardener volunteer and member of the Garden Club of Cape Coral.
Organic soil amendments. (n.d.). UF/IFAS Gardening Solutions. Retrieved from https://gardeningsolutions.ifas.ufl.edu/care/fertilizer/organic-matter.html
Shober, A., et al. (n.d.). Soil pH and the home landscape or garden. UF/IFAS Extension Solutions for Your Life EDIS. Retrieved from https://edis.ifas.ufl.edu/ss480