Ah, springtime is approaching quickly. You and I both know you’re getting anxious to get out into your gardens to grow your plants. I’m not faulting you, far from it. You’ll find that your local Extension agents want your garden to succeed as much as you do. Because we all want you to have a bountiful harvest, we need to have a conversation about fertility in your lawns and gardens.
Definitions
Before we get too deep into this topic, let’s define nutrition. You may hear some refer to fertilizers as “plant food.” While this is a common phrase concerning fertilizers, it is not factually accurate. Food is associated with energy creation within an organism. Plants are autotrophs, meaning they convert sunlight into energy. So, under this premise, sunlight is plant food, whereas plant nutrition is the building blocks of tissues or catalysts of metabolic processes.
The 17 elements designated as plant essential nutrients are categorized based on the quantity needed for healthy growth. All are important to have in your soil; as per the “Law of the Minimum,” your plant’s development will be limited based on the most deficient element.
UF/IFAS Photo
Macros
Those elements with the largest demand within the plant are known as macronutrients. The three most critical of these are very often absent in fertilizer conversations as they cannot be added to soil in granule form. These are carbon, hydrogen, and oxygen, and their presence in your garden results from your cultural practices. You get them from air and water in the pore spaces of your soil. Appropriate tillage and irrigation are the only ways to provide these elements to your plants. They are critical for proper photosynthesis and fluid balance in the plant.
The most discussed elements are so vital that they make up the three numbers on every bag of fertilizer. These are nitrogen (N), phosphorous (P), and potassium (K), all of which may be added to soil to overcome deficiencies (N often being the limiting factor). These elements are crucial for protein creation, photosynthesis, and fluid movement.
Secondary Nutrition
UF/IFAS Photo: J. Criss
The next set of nutrients have less demand than NPK. They are sulfur (S), magnesium (Mg), and calcium (Ca). Ca is essential for cell structure but is often abundant in our soils. S is frequently rained out of the atmosphere (though you may still need to add some) and facilitates enzymatic processes in plant cells. Mg needs the most attention in this category as it has a lot of mythology among gardeners. You’ve likely heard you should add this element to “green up” your plants. While it is true that Mg is critical to chlorophyll, adding it without testing for deficiencies first is a recipe for poor plant growth.
Micros
Our final category of fertilizer is micronutrients. These are iron (Fe), manganese (Mn), boron (B), chlorine (Cl), zinc (Z), copper (Cu), molybdenum (Mo), and nickel (Ni). These serve various functions in the plant, mainly in metabolic processes.
To Sum Up
Plant fertilization is critical for lawns and gardens. It behooves gardeners to understand these elements and their role in plant growth. Once you do, you’ll understand the importance of applying the correct version of the element in the proper amount at a time and location to maximize use efficiency. You can learn more about what they do and how they react in the soil here. For more information, contact your local extension office.
Palm trees are great for adding a tropical feel to your landscape. For the most part, they are easy to care for, however there are a number of environmental and nutritional factors that can affect palm tree growth. Extended drought conditions can cause palm trunk to contract or shrivel and extended periods of moisture can cause trunks to swell and crack.
A palm tree with an irregularly shaped trunk due to water stress. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Palm trees are monocots and do not have lateral meristems or vascular cambium. In dicot and coniferous trees these structures produce additional xylem (water transport structures) internally and phloem (nutrient transport structures) and bark externally. This means that once the apical meristem (frond producing portion of the palm) dies, the tree dies. It also means that wounds to the trunks of palms are visible for life instead of healing over like in dicots. If you were to cut the top out of a red maple, a number of it’s branches would fight to take over as the main trunk. If you were to cut the top out of a palm tree , you would be left with a dead snag for a tree. Palms certainly have unique structures and growing habits. Visit this publication from Dr. Timothy Broschat for more information on palm tree anatomy and morphology.
A palm tree with a wound near the base of its trunk. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Palm trees display nutritional disorders differently from other trees. Their nutritional balance gets disrupted if too much nitrogen is applied. This often happens when high nitrogen turfgrass fertilizers are applied near palm plantings. The recommended palm fertilizer is 8-2-12 (nitrogen-phosphorus-potassium) plus 4 magnesium all available in 100% slow release form. A soil test is recommended to determine if other micronutrients are needed in addition to magnesium.
Potassium-deficient older leaf of Dictyosperma album (hurricane palm) showing translucent yellow-orange spotting. Photo Credit: Timothy K. Broschat, University of Florida/IFAS
This article provides just a glimpse of some of the common issues that affect palms. For more information on what could be going on with your palm trees and general palm tree care please visit Ask IFAS: Palm Care.
Feed the hungry and meet a challenge; donate peanut butter to UF/IFAS Extension !
If you want to help feed the hungry in Florida’s Panhandle this year, you can donate peanut butter during the annual Peanut Butter Challenge, coordinated by UF/IFAS Extension.
Thanks to a partnership of UF/IFAS Extension and the Florida Peanut Producers Association, food pantries from Pensacola to Monticello will receive thousands of jars of donated peanut butter this December.
From Oct. 1 through Nov. 21, you can donate unopened jars of peanut butter at your UF/IFAS Extension county office. Each year, one or more UF/IFAS Extension agents at your local county extension office collect unopened peanut butter jars.
Since 2012, the volunteers and UF/IFAS Extension faculty have collected jars of peanut butter from residents, volunteer groups and businesses in 16 northwest Florida counties. Last year, UF/IFAS Extension county offices received 6,222 jars of peanut butter, said Libbie Johnson, agricultural agent for UF/IFAS Extension Escambia County and co-organizer of the Challenge.
In addition to these donations, the Florida Peanut Producers Association also contributes, supplying more than 3,000 jars each Challenge, Johnson said.
They hope to surpass that total this year with your support and contributions.
“The Peanut Butter Challenge not only raises awareness about the important contribution of North Florida’s peanut growers to the state peanut industry, but also helps provide a healthy, locally produced product to food-insecure families in northwest Florida,” Johnson said.
Visit your local county extension office today and donate some peanut butter to support nutrition in your local panhandle community! (Press Release authored by UF / IFAS Communications)
The Jackson County Master Gardeners are hosting a hosting a Mushroom Growing Workshop on Saturday, February 10 at the Jackson County Extension Office, 2741 Penn Ave., Marianna, FL.
Shiitake mushrooms growing on a log. Photo Credit: University of Florida/IFAS
MUSHROOM GROWING WORKSHOP
SATURDAY, NOVEMBER 18
9:00 AM to 2:00 PM
• Learn to grow shiitake mushrooms on logs.
• Learn about mushroom nutrition.
• Take home an inoculated mushroom log!
• A home cooked lunch is included!
Registration Fee $20.00
Includes Lunch
Space is Limited
To register, contact the Extension Service at (850)482-9620 or s.farr@ufl.edu.
Pre-register by February 7th.
“We have replaced this grass several times over the past few years; and it’s dying again.” I have heard this complaint too many times this summer. Last summer’s heavy rain, the stress of January’s icy weather, and this year’s extended summer have contributed to widespread outbreaks of Take-All Root Rot, a soil-inhabiting fungus Gaeumannomyces graminis var. graminis.
Symptoms of Take-All-Root-Rot. Photo credit: Sheila Dunning, UF/IFAS.
This disease causes yellow grass patches ranging in diameter from a few inches to more than 15 feet. The symptoms first appear in the spring, but the disease can persist all summer and survive the winter. Over time, the entire area dies as the root system rots away. The pathogen is naturally present on warm-season turfgrass roots. High rainfall and stressed turfgrass trigger the disease.
Since the roots are affected, they are not able to efficiently obtain water or nutrients from the soil, nor are they able to store the products of photosynthesis, which result in the loss of color in the leaves. By the time the leaf symptoms appear, the pathogen has been active on the roots for several weeks, probably longer; the disease has been there potentially for years. If the turfgrass is not stressed, leaf symptoms may never be observed.
This disease is very difficult to control once the aboveground symptoms are observed. Measures that prevent or alleviate stress are the best methods for controlling the disease. Any stress (environmental or manmade) placed on the turf weakens it, making it more susceptible to disease. Remember, that every maintenance practice, fertilizer application, and chemical (especially herbicide), application has an impact on turfgrass health. Cultural practices that impact the level of stress experienced by a lawn include:
proper turfgrass species selection
mowing at the correct height
irrigation timing, frequency and volume
fertilizer: nitrogen and potassium sources and application quantities
thatch accumulation, and
soil compaction
The selection of turfgrass species should be based on existing soil pH, sunlight exposure, use of the area and planned maintenance level.
Mower blades must be sharp to avoid tearing of the leaves. Additionally, turfgrasses that are cut below their optimum height become stressed and more susceptible to diseases, especially root rots. When any disease occurs, raise the cutting height. Scalping the grass damages the growing point. Raising the cutting height increases the green plant tissue available for photosynthesis, resulting in more energy for turfgrass growth and subsequent recovery from disease.
If an area of the lawn has an active fungus, washing or blowing off the mower following use will reduce the spread of the disease to unaffected areas.
The amount of water and the timing of its application can prevent or contribute to disease development. Most fungal pathogens that cause leaf diseases require free water (rainfall, irrigation, dew) on the leaf to initiate the infection process. Irrigating every day for a few minutes is not beneficial for the turfgrass because it does not provide enough water to the root zone, but it is beneficial for turfgrass pathogens. It is always best to irrigate when dew is already present, usually between 2 and 8 a.m., and then only apply enough water to wet the root zone of the turfgrass.
Excessively high nitrogen fertility contributes to turfgrass diseases. The minimum amount required for the grass species should be applied. Potassium (K) is an important component in the prevention of diseases, because it prevents plant stress. Application of equal amounts of nitrogen and potassium is recommended for turfgrass health. When turfgrass roots are damaged from disease, it is beneficial to apply nutrients in a liquid solution. However, nitrate-nitrogen increases the severity of diseases, so their use should be avoided when possible. Ammonium-containing fertilizers are the preferred nitrogen sources.
Heavy liming has also been linked to increases in Take-All Root Rot. Since most turfgrasses can tolerate a range of pH, maintaining soil at 5.5 to 6.0 can suppress the development of the pathogen. When the disease is active, frequent foliar applications of small amounts of nutrients is necessary to keep the turfgrass from declining.
Additional maintenance practices that need to be addressed are thatch removal and reduction of soil compaction. Excessive thatch often causes the mower to sink which can result in scalping and reducing the amount of leaf tissue capable of photosynthesizing. Thatch and compacted soil prevent proper drainage, resulting in areas remaining excessively wet, depriving root systems of oxygen. Since recovery of Take-All-Root-Rot damaged turfgrass is often poor, complete renovation of the lawn may be necessary. Removal of all diseased tissue is advised.
As a native soil-inhabiting pathogen, Take-All-Root-Rot cannot be eliminated. However, suppression of the organism through physical removal followed by proper cultivation of the new sod is critical to the establishment of a new lawn. Turfgrass management practices, not chemicals, offer the best control of the disease.
It is acceptable to use fungicides on a preventative basis while rooting in the sod. Azoxystrobin, fenarimol, myclobutanil, propiconazole, pyraclostrobin, thiophate methyl, and triadimefon are all fungicides that can be utilized to prevent disease development while having to excessively irrigate newly laid sod. Ideally, the turf area should be mowed and irrigated prior to a fungicide application. Unless the product needs to be watered in, do not irrigate for at least 24 hours after a chemical treatment. Do not mow for at least 24 hours, to avoid removal of the product attached to the leaf blades.
With all the stresses that our lawns have experienced, it is very important to continue monitoring the turf and be cautious about the cultural practices being used. Take-All Root Rot is likely to flourish. Do not encourage its development. A pathology test with the University of Florida Laboratory can confirm the presence of the disease causing organism. Before resodding again, have the dying sod tested.
