One of the best things about gardening is the opportunity it presents to learn new things.
We gain garden wisdom through trial and error, experimenting with plants and techniques, and solving problems.
Each of us has our way of gardening.
But some anecdotal advice is not the best approach to keep plants healthy.
Here are some common garden myths and why we should avoid them.
• Myth No. 1 – Add lime when planting vegetables.
Many Florida soils are naturally acidic – although soils can be alkaline with a high pH. Soil pH may be high in some compost blends and fill material. Well or irrigation water also can have a high pH. It’s important to know the pH because plants grow best within a pH of 5.5 – 7.0. It’s within this range that most nutrients are available to plants.
A better approach: Instead of adding lime before planting vegetables, get the soil pH tested from a Florida lab.
Lime increases soil pH, and it is very difficult to reverse the effects of over-liming.
Don’t add lime without a soil test. If your soil comes back high in pH, other options include: Choose a different type of soil (for example, bagged vs. bulk), plant in another location that has a preferred pH, use raised beds, or select plants that will tolerate the current soil pH.
• Myth No. 2 – Make homemade pest control with dish soap.
There are many homemade recipes available online and through word-of-mouth. Dish soap is commonly touted as an ingredient for inexpensive, home remedies. However, most dish soaps are not registered or labeled as insecticides. Dr. Adam Dale and Matthew Borden, UF/IFAS, have a helpful publication called Managing Plant Pests with Soaps. In this publication, they explain that “all soaps are not the same” and dish soaps are “not an organic alternative to pesticides.”
Dish soaps are often powerful detergents used for cleaning and degreasing. These detergents are not intended for use on plants or for pest control. Dish soaps can damage plants and do not discriminate between beneficial insects and pest insects. Some of the recipes lack information about application rates, targeted pests, and other considerations, such as not applying to stressed plants or when temperatures exceed 90° F.
A better approach: Instead of using homemade dish soap recipes for pest control, use labeled insecticidal soaps. These products are affordable – like the homemade recipes – and available at garden centers and landscape supply companies. The label explains application rates and they are generally safe for use on plants, when used according to the label. Insecticidal soaps – not dish soaps – are effective on a range of pests with soft bodies. These pests include aphids, mealybugs, scales, spider mites, thrips and whiteflies. Read and share the above-referenced publication for more information.
• Myth No. 3 – Plant tomatoes in the summer.
Our hot summers are not the best time to plant tomatoes. Cooler months are better for Florida tomatoes.
A better approach: Plant tomatoes in Central Florida from January through February and then again from August through September. Want to learn the best time to plant other vegetables in Florida? Use the UF/IFAS Florida Vegetable Gardening Guide, Table 1, for a list of planting times.
• Myth No. 4 – Paint tree wounds.
In the past, it was standard practice to paint tree wounds or freshly cut surfaces. The idea was that by painting the wounds, the tree would be protected from cracking and wood-rotting organisms. However, tree studies have shown that wound dressings do not prevent decay. The painted surface may still crack when exposed to the sun, and moisture can build up between the wood and the wound covering. Trees with painted wounds may even invite wood-rotting pests compared to trees without painted wounds.
A better approach: Leave the cut surface alone. There is no need to apply paints, wound dressings, or chemical formulations to the surface of the cut because they don’t prevent decay.
• Myth No. 5 – Hurricane prune palms.
In general, palms rarely need pruning. The idea of hurricane pruning is to remove most of the fronds to make the palm more resistant to wind damage. However, palm observations have shown the opposite is true!
Many hurricane-pruned palms fared much worse after hurricanes – they were weaker and suffered more damage – than palms that had not been hurricane-pruned. Additionally, over-pruning may attract pests, such as palmetto weevils. Too much pruning can make nutrient deficiencies worse. Over-pruning may stress the palm, making it less able to withstand disease.
A better approach: Take good care of your palms by not over-pruning them. Only prune dead or dangerous fronds. Don’t “hurricane” prune or trim them into pineapple shapes.
• Myth No. 6 – Use Epsom salts on palms.
Epsom salts have been recommended as an inexpensive palm fertilizer. However, the nutrients contained in Epsom salts are quick-release, water-soluble magnesium sulfate. And, the use of quick-release fertilizers can harm palms.
A better approach: Research by UF/IFAS indicates slow-release nutrients are better for palms. A good palm fertilizer is the 8N-2P2 O5 – 12K2O +4Mg, with micronutrients and prilled kieserite (a less water-soluble form of magnesium sulfate than Epsom salts). This fertilizer also is called the “palm special” fertilizer. Garden centers, local nurseries, and professional landscape supply companies may carry this fertilizer. Check the label to verify that 100% of the N, K and Mg are in a slow-release form. Use the “palm special” fertilizer and not Epsom salts.
To find out more, check these references that were used for this column.
References: Borden, M. A. and A. G. Dale. (2019). Managing Plant Pests with Soaps. IFAS Publication Number ENY344. Gainesville: University of Florida Institute of Food and Agricultural Sciences. Retrieved from https://edis.ifas.ufl.edu/pdf/IN/IN124800.pdf.
Broschat, T. (2017). Fertilization of Field-Grown and Landscape Palms in Florida. IFAS Publication Number ENH1009. Gainesville: University of Florida Institute of Food and Agricultural Sciences. Retrieved from https://edis.ifas.ufl.edu/pdf/EP/EP26100.pdf.
Park Brown, S., D. Treadwell, J. M. Stephens, and S. Webb. (2020). Florida Vegetable Gardening Guide. IFAS Publication Number SP 103. Gainesville: University of Florida Institute of Food and Agricultural Sciences. Retrieved from https://edis.ifas.ufl.edu/pdf/VH/VH02100.pdf.
For additional information, contact or 813-744-5519, ext. 54145.
Nicole Pinson is the Urban Horticulture Agent in Hillsborough County.
Published June 30, 2021
