Fertilization is a subject that throws many a gardener for a loop. It can be confusing, and we in the professional horticulture world understand. This topic will almost always be approached from the prospective of nitrogen. So why does nitrogen get so much attention? What is its role in plant growth? Nitrogen is the primary driver of protein synthesis, plant metabolism, energy creation, and is the structural component in chlorophyll. These are all extremely important functions leaving little doubt as to why it’s so critical. Your plants use this resource abundantly for healthy growth. The reason it gets so much attention is owing to its frangibility in the soil. Nitrogen goes through changes once applied to soils and is readily lost to the environment. For this reason, nitrogen application needs to be timed appropriately, and your cultural practices need to be such that encourage plant uptake over losses to the environment. Fear not my friends, this article will bolster your insight into the wonderful world of nitrogen, and have your plants growing strong and healthy.
The What and Why of Nitrogen
Nitrogen is one of three macronutrients identified in every fertilizer bag as the first of three numbers. This standardized NPK labeling refers to the amount of this nutrient in the bag by percentage of total weight. Application rates should be based on this number, and how much nitrogen you’ll need to cover a specified area. which number you use is based on the equipment you have to apply more so than the plant requirements.
UF/IFAS Photo: Dan Culbert
Nitrogen can be natural or man made. Natural sources come in the form of composts, manures, and through atmospheric deposition. The later of these sources means rain, which washes nitrogen out of the atmosphere and into your soils. Man made sources conversely come in bags and are the result of a combustion process developed by Fritz Haber, and Carl Bosch circa 1910. Either way, nitrogen will be in the form of ammonia, nitrate, ammonium, or urea. Knowing this is important as it will dictate application methodologies. For instance, urea applied to the surface will escape into the atmosphere if not incorporated into your garden.
UF/IFAS photo: T.W. Shaddox
Nitrogen type will also affect soil pH. This is especially important with ammonia-based fertilizers as residual acidity from them may lower pH. Applying the correct type will mitigate large unwanted changes in soil. Why are we concerned with soil pH? It speaks to nutrient availability and, thus how well your plants grow. It can be overwhelming, but with soil testing and a call to your extension office, it’s easy to identify the appropriate fertilizers for your application.
Reactions in Soils
Soil is often considered inert, holding plants in place while providing a pantry full of the nutrients they crave. Nothing is further from the truth. Soil is a living entity with its own physical and chemical properties. The addition of anything, including irrigation, affects these properties.
Nitrogen takes two forms in your soil aside from nitrogen source. Inorganic nitrogen is converted from soil organic matter in a process known as mineralization or added from bagged fertilizers and is available for plant uptake. Organic nitrogen is unavailable for plant uptake and will be present in the natural forms listed in the previous section. Both are susceptible to the nitrogen cycle and may be lost to the environment. This happens as water passes through soil (leaching), erosion, runoff, or is lost to the atmosphere through volatilization and may have negative effects on surrounding water bodies.
UF/IFAS Photo
To mitigate these risks through responsible fertilizer application, irrigation management, and landscape design. Apply fertilizers when plant uptake is favorable, and only to the level required by your plants. This will be during heavy vegetative growth periods such as initial installation. Irrigate as dictated by your plant life vs on a timer. Watering is a vital practice, but often overdone. Keep water levels enough to avoid plant stress but not excessive. Doing so reduces leaching potential and will keep your plants healthier. Finally, design your landscape with Florida Friendly Landscaping principles. Integrate diverse plant life, including turfgrasses and landscaped beds. The goal here is to allow enough plant life to absorb excess storm water, and support local pollinator populations.
Nitrogen is a critical piece of your fertilizer routine. It’s important to understand how it reacts with both your plants and your soils. A little knowledge can go a long way to keeping your plants healthy while mitigating risks from over fertilization. For more information, see this Ask IFAS document, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.
For me, tomatoes are the most difficult (and expensive) vegetable to grow. I even try to discourage people from growing tomatoes in Florida. Tomatoes are susceptible to damage from a plethora of diseases and insect pests AND they require a lot of maintenance and fertilizer. However, I now have a tomato variety I can recommend – The Everglades Tomato.
The Everglades tomato (Solanum pimpinellifolium) is a different species than the traditional tomato (Solanum lycopersicum). Other names for this tomato are the wild tomato or currant tomato. The plant produces an abundance of small tomatoes (about 1/2 inch diameter) with thin skin. Unlike most tomatoes, Everglades tomatoes keep producing throughout the heat of summer. They are even tolerant of brackish water and salt winds.
Everglades tomatoes should be cared for like any other indeterminate (vining type) tomato. Like most gardeners, I like to plant tomatoes a little deeper (two inches or so) than they were planted in the tray/pot. This allows for more adventitious roots to develop from the buried portions of the stems. I also like to trellis these plants with tall stakes and twine or some other support to improve air circulation. However, I have read that Everglades tomatoes grow just fine rambling on the ground. Make sure to give them a little more space than other tomatoes regardless if you stake them or not. Fertilize and irrigate just the same as you would for other tomatoes.
A bountiful harvest of Everglades tomatoes. Photo Credit: Connie Gladding, Master Gardener Volunteer, University of Florida/IFAS Extension – Clay County
Of course, just like any plant, Everglades tomatoes aren’t perfect. Their small size makes harvesting a little more labor intensive and their thin skin is easily torn. But I’m able to look past these faults because of their excellent flavor. I’ve also noticed Everglades tomatoes are not immune to caterpillar/moth pests. Fortunately the caterpillars only seem to feed on the leaves, because the tomatoes are so small.
Whether you’re a chef or just want a sweet snack, you should give Everglades tomatoes a try. Just search the internet for seed sources or ask a friend for a cutting.
When you hear the word “pollinator”, what is the first insect that comes to mind? If I had to guess, you would probably say honey bee. European honey bees play an important role in agriculture as pollinators and honey producers, but there are hundreds of native pollinators often overshadowed by the beloved honey bee you should know about, too!
One such group of pollinators native to Florida are sweat bees. Sweat bees get their unfortunate name from their nutritional requirements of salt that are sometimes sourced from sweaty humans. They rarely sting but are capable, and they can certainly be annoying to people when they lick salt off their skin. This behavior tends to get more attention than their important role as pollinators.
A subgroup of sweat bees are furrow bees. Furrow bees nest in the ground or rotting wood and may be solitary or eusocial. In-ground nests are composed of branching tunnels in sandy soil at a depth between 8 inches and 3 feet with a small entry roughly the size of a pencil. Within the tunnels, the mother creates individual cells stocked with nectar and pollen and lays an egg. The larva feeds on these provisions and pupates underground eventually emerging as an adult. The life cycle can vary from a few weeks to a year or more depending on species and environmental conditions.
Furrow bees are generalist feeders which means they will visit many different flowers, so diverse landscapes are attractive to them. In my northwest Florida garden, I see them often on sunflowers, Black-eyed Susan, coneflower, cosmos, tithonia, zinnia, and tickseed.
Poey’s Furrow Bee is a common visitor to sunflowers. J_McConnell, UF/IFAS
Moderate to strong El Nino conditions were predicted for this summer and I think this revelation has come true. The heat and humidity in the latter part of June were on the verge of being unbearable and the precipitation cycle is unpredictable. In the middle of the month, a series of storms with strong winds hit a number of areas in the panhandle, bringing down some large trees. University of Florida/IFAS Extension recommends removing large branches and trees that pose a threat to damaging your home and other structure before the start of each hurricane season. However, sometimes we just don’t get around to removing these trees until after they fall.
Trees laying on the corner of a house. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Luckily only the tops of the trees in the photo above fell on the roof of the house. These are laurel oaks (Quercus laurifolia) which are fast growing but not tolerant of wind. In this situation, four trees fell together and are laying on the corner of the roof. The trees also pulled down the power, cable, and phone lines to the house.
So where do we go from here? Unfortunately the trees were uprooted and pose the potential for additional harm to the house if not removed correctly. In this situation, a tree service that owns a crane was recommended to remove the trees without administering more damage to the home and other trees and plants in the landscape and to avoid knocking down the powerlines again.
A crane used in conjunction with a boom lift to cut and lift trees off of a house. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
The tree service utilized a boom lift and a crane to safely lift the trees away from the house and utility lines. The employee on the lift connected each section of the tree to the crane before each cut. The boom was then moved to a safe location before each tree section was lifted away to the road to be cut into smaller pieces.
In this situation, the homeowner was lucky. There was no damage to the house other than a couple bent panels on the metal roof. However, this little bit a damage could have been totally avoided if these weak trees had been removed before the storm hit.
The trees featured in this article fell during a thunderstorm and possible tornado. If these trees had fallen during a weather event that was Federally declared, then a portion of the cost for their removal and cleanup might have been eligible to be considered an itemized deduction on Federal income tax forms. For more information on filing this type of loss please read the publication “Income Tax Deduction on Timber and Landscape Tree Loss from Casualty” from the USDA Forest Service.
Homeowners may consider growing Frogfruit, Phyla nodiflora as a companion plant in turf areas. Learn the qualities of this groundcover with UF IFAS Extension Escambia County.
