by Les Harrison | Aug 11, 2017
July’s hot summer weather has given way to August’s 31 days of what will likely be temperatures and humidity equally elevated and intense. Wishes for November’s cooler thermometer reading are already creeping into daily conversations. The lawns and gardens in Wakulla County have rains as a mitigating factor to counteract the wilting potential of normal to excessive temperature readings. Unfortunately the arrival of water from above is not on a set or easily predictable schedule.
Traditionally, summer is the wettest season in Florida, with more than half of the annual rainfall occurring during the June to September “wet season”. Florida’s highest average annual rainfall occurs in the Panhandle with averages exceeding 60 inches per year. The Pensacola and Tallahassee weather stations are listed among the ten “wettest” stations in the nation. Still, this pattern of seasonal precipitation can vary greatly between locations, years and even days. This variability often results in the need to water the lawn, landscape and garden. By following a few guidelines, you can produce the best results for plants under stress and conserve a vital and limited resource.
It is most efficient to apply water between 5:00 a.m. and 10:00 a.m. for several reasons. Only water that is in contact with roots can be absorbed by the plant. If water is applied after 10:00 a.m., a substantial portion of it will evaporate before it reaches the roots; more will then need to be applied and this resource’s productivity will be reduced. Never water late in the afternoon as evaporation will still be a problem, and wet turf and plants will invite a variety of fungal diseases to flourish as night settles.
Photo Courtesy: Les Harrison, UF/IFAS Wakulla County Extension
In the case of landscapes and gardens, water should be applied only when the moisture in the root zone system has been depleted to an unacceptable level, usually by 1/2 to 2/3 of the stored soil-water. There are several ways to determine when the soil-water reservoir has been depleted beyond an acceptable level. The simplest method is a visual inspection of the turf or plants. Common symptoms of water stress include leaf color changes to a bluish-gray tint, footprints which linger long after being pressed into the grass and curled or folded leaf blades. Be sure the sprinklers are delivering water to the target area as water which misses the soil and is applied to hard surfaces such as driveways and sidewalks will be wasted. It also may pose an environmental problem in the form of runoff. Surface runoff that flows past the landscape will usually reach streams, ponds, or the Gulf of Mexico. If it picks up pollutants along the way, they too will reach the surface water bodies.
Over watering can be just as damaging as too little water. Excessive irrigation water can infiltrate the ground and reach groundwater aquifers. This issue is complicated when groundwater runs close to the surface. Excessive nutrients or pollutants can be discharged into surface bodies or move vertically into the deeper land layers. The connected springs and sinkholes in Wakulla County make the movement of surface water a common concern. Responsible and efficient irrigation will have positive effects far beyond the front yard.
To learn more about the effective use of water in Wakulla County’s landscapes, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or http://wakulla.ifas.ufl.edu/
by Mark Tancig | Aug 1, 2017
Florida’s panhandle has received quite a bit of rain this summer. In the last three months, depending on the location, approximately 15 to 35 inches of rain have come down, with the western panhandle on the higher end of that range. In addition to the rain, we all know how hot it has been with heat index values in the triple digits. And who can forget the humidity?! Well, these weather conditions are just the right environmental factors for many types of fungi, some harmful to landscape plants, most not.
In the classification of living things, fungi are divided into their own Kingdom, separate from plants, animals, and bacteria. They are actually more closely related to animals than plants. They play an important role on the Earth by recycling nutrients through the breakdown of dead or dying organisms. Many are consumed as food by humans, others provide medicines, such as penicillin, while some (yeasts) provide what’s needed for bread and beer. However, there are fungi that also give gardeners and homeowners headaches. Plant diseases caused by various fungi go by the names rusts, smuts, or a variety of leaf, root, and stem rots. Fungal pathogens gardeners may be experiencing during this weather include:
- Gray leaf spot – This fungus can often show up in St. Augustine grass lawns. Signs of this fungus include gray spots on the leaf (very descriptive name!). This disease can cause thin areas of lawn and slow growth of the grass.
Gray leaf spot on St. Augustine grass. Credit: Phil Harmon/UF/IFAS.
- Take-all root rot – This fungus can attack all our warm-season turfgrasses, and may start as yellow leaf blades and develop into small to large areas of thin grass or bare patches. The roots and stolons of affected grasses will be short and black.
Signs of take all root rot. Credit: UF/IFAS.
Powdery mildew – This fungus can be found on many plants, from roses to cucumbers. It looks like white powder on the leaves and can lead to plant decline.
- Armillaria root rot – This fungus can infect a variety of landscape plants, including oaks, hickories, viburnums, and azaleas. Symptoms can include yellowing of leaves and branch dieback, usually in adjacent plants. Old hardwood stumps can harbor this fungus and lead to the infection of nearby ornamentals.
Because fungi are naturally abundant in the environment, the use of fungicides can temporarily suppress, but not eliminate, most fungal diseases. Therefore, fungicides are best used during favorable conditions for the particular pathogen, as a preventative tool.
Proper management practices – mowing height, fertilization, irrigation, etc. – that reduce plant stress go a long way in preventing fungal diseases. Remember that even the use of broadleaf specific herbicides can stress a lawn and exacerbate disease problems if done incorrectly. Since rain has been abundant, irrigation schedules should be adjusted to reduce leaf and soil moisture. Minimizing injury to the leaves, stems, and roots prevents stress and potential entry points for fungi on the move.
If you think your landscape plants are suffering from a fungal disease, contact your local Extension Office and/or visit the University of Florida’s EDIS website at http://edis.ifas.ufl.edu for more information.
by Sheila Dunning | Jul 21, 2017
(UF/IFAS photo Thomas Wright)
Northwest Florida’s weather patterns can present challenges to maintaining a health lawn. Heavy rains promote fast growth and relentless sunshine causes lawns to fade. In the last 200 days we have received at least 68 days of rain. While the rest of Florida was experiencing record drought, the Panhandle was experiencing torrential downpours. With every drop of rain your spring fertilizer is being metabolized by the lawn, reducing how many nutrients remain in the soil. Even the best slow-release fertilizer will only last 3-4 months. The message is: “It’s time for more fertilizer.”
A healthy lawn is an important component of the urban landscape. Not only do lawns increase the value of a property, they also reduce soil erosion, filter stormwater runoff, cool the air, and reduce glare and noise. A healthy lawn effectively filters and traps sediment and pollutants that could otherwise contaminate surface waters and groundwater. Lawns require nutrients throughout the growing season to stay healthy. In Northwest Florida the growing season is typically April to October.
Proper fertilization consists of selecting the right type of fertilizer and applying it at the right time and in the right amount for maximum plant uptake. The type of fertilizer should be based on a soil test, available through UF/IFAS Extension. The timing of application and amount of fertilizer is dependent on the research-based recommendations for the grass species and the fertilizer analysis of the product being used.
Chart excerpted from Florida Friendly Landscaping publication
Select only a fertilizer that states that the product is for use on residential turf. Do not use a fertilizer meant for flower or vegetable gardens on lawns. By Florida Administrative Code, Rule 5E-1.003, the Urban Turf Rule requires that the fertilizers being applied to residential lawns are labeled for the site and the application rates be followed. Typically, these products will contain both slow-release nitrogen and low or no phosphorus. Slow-release nitrogen will provide a longer-lasting response from the grass and reduces the potential for burning. For more information on the Urban Turf Rule go to: http://www.edis.ifas.ufl.edu/pdffiles/EP/EP35300.pdf.
With frequent rain the soil is also losing iron. Keep in mind that the green fading to yellow appearance in your lawn may be an iron deficiency. Before applying your summer fertilizer put out a liquid chelated iron. It will improve the health of the lawn while you are trying to find a dry day to fertilize. While it is necessary to water in fertilizer with ¼” of water to reduce burn potential and volatilization, never apply fertilizer when heavy rain is expected. The rainfall over ¼” can encourage runoff and/or leaching of that fertilizer, which can be costly and environmentally harmful.
by Blake Thaxton | Jul 21, 2017
Northwest Florida has experienced an enormous amount of rain this summer. The western panhandle has received over 29 inches of rain since the beginning of May according to the Florida Automated Weather Network station at the West Florida Research and Education Center in Jay, Florida. That is 44% of average annual rainfall in less than two months. All of this rain has probably thrown off the normal lawn mowing routine. It is hard to get out and mow the lawn when its pouring buckets or the lawn resembles a swamp. With all of this in mind, there are a couple of mowing pointers that would be useful to implement to address the out of control lawn growth and the challenges posed by not being able to stick to normal mowing schedule.
- Always attempt to mow at the IFAS recommended height for your species of turfgrass. The recommended heights are determined by how quickly the species grow in our climate. The chart below shows the best heights at which to mow your lawn. The fine textured zoysiagrasses are not listed but should be mowed at 0.5 to 1.5 inches. Check the lawn mowers mowing height by measuring the distance from the ground to the bottom of the mowing deck on a flat surface.
From Mowing Your Florida Lawn: http://edis.ifas.ufl.edu/pdffiles/LH/LH02800.pdf
- When you do get out to mow, never remove more than 1/3 of the leaf blade. If you cut to short you will “scalp” the turf and cause a brown look on the lawn. This can be damaging to the turf and allow for weeds to get established by exposing the soil to the sunlight. What is taking place more in northwest Florida is not mowing frequently enough and cutting off excess growth due to the rain. This also can cause scalping so it is very important to mow frequently enough to only remove 1/3 of the leaf blade.
A zoysia lawn that has been “scalped” after excess growth and infrequent mowing. (Photo Credit: Blake Thaxton)
Other practices such as keeping your mower blade sharp, mowing in different directions, and leaving clippings on the ground will help keep a healthy Florida lawn. Please see more information about mowing correctly in Florida in the University of Florida/IFAS Extension publication: Mowing Your Florida Lawn
by Matthew Orwat | Jun 16, 2017
Slime Mold Sporangia. Image Courtesy Matthew Orwat
Although black or white streaks are shocking when they appear on an otherwise healthy lawn, slime molds are rarely harmful.
Slime mold is actually caused by the reproductive structures of an array of different organisms, classified as plasmodia or Protista, which are regularly present in the soil. They are often mistaken for fungi. The different types are referred to as myxomycetes or dictyosteliomycetes. They usually appear on warm humid days in late spring or early summer after extended periods of rain. This extended period of heat and humidity, as is currently being experienced in the Florida Panhandle, initiates the perfect climate for slime mold development.
While regularly present in the soil, they usually make a visual appearance on warm humid days in late spring or early summer after extended periods of rain. This extended period of heat and humidity, currently being experienced in the Florida Panhandle, initiates the perfect climate for slime mold development.
As depicted in the picture, slime mold makes the lawn look like it was just spray-painted with black or grey paint. They can sometimes be pink, white, yellow or brown as well. The round fruiting bodies, called sporangia, carry the spores which will give rise to the next generation of the mold. After a few days the sporangia will shrivel up, release the spores and leave no noticeable trace on the lawn.
Closeup: Slime Mold in Centipedegrass. Image courtesy Matthew Orwat
Currently, no fungicide exists to control slime mold because chemical control is not necessary. An excellent method to speed up the dissipation of slime mold is to mow or rake the lawn lightly. This will disturb the spores and hasten their departure. Another effective removal method is to spray the lawn with a forceful stream of water. This process washes off the slime mold sporangia and restores the lawn to its former dark green beauty.
Excessive thatch accumulation also increases the probability of slime mold occurrence.
For more information consult your local county extension agent consult the UF / IFAS Slime Mold Fact Sheet, or read the Alabama Cooperative Extension publication Slime Mold on Home Lawns.
Slime Mold in Centipedegrass. Image Courtesy Matthew Orwat
by Larry Williams | Jun 10, 2017
Typical ground pearl damage to lawn. Photo Credit: Larry Williams
There are numerous reasons why maintaining a North Florida lawn is challenging and ultimately frustrating.
One such reason is ground pearls.
Ground pearls, small-scale insects that bother turfgrass roots, are soil dwelling pests that are not much of a problem in northern lawns. But they are quite the problem in North Florida lawns.
Most people, having never heard of ground pearls, may blame weeds, mole crickets and a multitude of other possible causes for their lawn’s demise. But in the last two to three years, this insect seems to have become more of a problem in many of our lawns, including mine.
Unfortunately, there is no effective chemical control for ground pearls in lawns.
Ground pearls feed on roots of bermudagrass, bahiagrass, St. Augustinegrass and zoysiagrass but prefer centipedegrass. They suck juices from the roots. Their feeding eventually causes areas of the lawn to thin and die out to bare ground, especially when the grass is under stress due to drought, nutritional deficiencies, etc.
Reddish adult female ground pearl & immature “pearl” stage. Photo credit: Larry Williams
Many times, the dying areas are somewhat circular or serpentine in pattern. Sometimes the circular areas coalesce, forming larger, irregular shaped dying areas. Weeds tend to invade infested areas.
The quote below, taken from a UF/IFAS Extension publication on this insect, provides some insight into their life cycle. “Clusters of pinkish-white eggs, covered in a white waxy sac, are laid in the soil from March to June. Tiny crawlers attach to roots and cover themselves with a hard, yellowish to purple, globular shell. These “pearls” range in size from a grain of sand to about 1/16 inch. They may occur as deep as 10 inches in the soil. The adult female is 1/16 inch long, pink in color, with well-developed forelegs and claws. Adult males are rare, tiny, gnat-like insects. One generation may last from 1 to 2 years.”
It is the immature stage (nymphs), which look somewhat like tiny pearls from which they get the “ground pearl” name. In this stage, they look like tiny shiny pearls once they are uncovered and exposed to sunlight. They are less than a BB in size. They overwinter in the “pearl” stage.
The ineffectiveness of insecticides is at least partly due to the ground pearl’s ability to avoid insecticides because of being protected in the soil and because of the prolonged protective “pearl” stage of its life cycle.
Since there are currently no biological or chemical controls that work, it’s recommended to minimize lawn stress and maintain proper fertilization and irrigation to help grass tolerate the damage.
Additional information on ground pearls is available at the following UF/IFAS Extension publication “Ground Pearls”.
