by Julie McConnell | Mar 2, 2016
Those familiar with the Florida-Friendly Landscaping™ Principles know that the number one rule is Right Plant, Right Place. But proper timing is important and should not be discounted! Experienced gardeners recognize that certain flowering and annual vegetable plants have distinctive seasons, but may not realize that turfgrass is seasonal, too.
Warm season and cool season turfgrasses fall into the classes of either annuals and perennials. In North Florida, the most commonly grown turfgrasses are warm season perennials such as Zoysiagrass, Bermudagrass, Centipedegrass, and St. Augustinegrass. These grasses thrive in warm weather and, although they may slow down or even turn brown in the winter, are still very much alive and resume growth readily in the spring. Because they are warm weather lovers, plan to seed one of these species when soil temperatures are warm enough for successful seed germination and when young new grass has enough time to become established without danger of frost damage.
Annual ryegrass label says to plant early spring – but that is too late in North Florida. Photo: Julie McConnell, UF/IFAS
On the flip side there are cool season grasses such as fescue, ryegrass, and bluegrass. These grasses prefer cool weather and do poorly and may go dormant or die when subjected to hot weather. These grasses may be perennials in other areas of the country, but should be treated as cool season annuals if grown in Florida. Cool season grasses may be used as a groundcover in bare spots or to overseed warm season grass from fall through early spring.
When purchasing turfgrass seed, be sure to check with your local extension office to verify that the timing is right for that particular grass. Seed products sold locally may have recommendations that are more relevant to northern climates and performance will differ.
For more information about seeding lawns please read Establishing Your Florida Lawn
by Larry Williams | Oct 6, 2015
Fertilizer: Image Credit UF / IFAS
In Northwest Florida, all of our lawn grasses begin to fade and slowdown in growth during fall.They are supposed to go dormant. Some will go dormant earlier than others based on species, location and management.
The grasses we use to create lawns are warm season grasses such as centipedegrass, St. augustinegrass, bahiagrass, bermudagrass and zoysiagrass.
The cooler temperatures (particularly cooler night temperatures) and the shorter days of autumn trigger these grasses to slow down. Their color begins to fade and eventually they turn brown, usually after a frost or freeze.
Fertilizer Spreader: Image Credit UF / IFAS
As these warm season grasses go dormant, they don’t need to be fertilized, particularly with a high nitrogen fertilizer. Some of the so called “winterizer” fertilizers available in our area can cause more damage than good despite the advertisements.
Nitrogen encourages new growth and interferes with the dormancy process, forcing the lawn to produce new tender growth at the wrong time of year. This sets the lawn up for damage. That young tender growth is very susceptible to cold injury and is likely to be damaged by the first frost. This greatly weakens the lawn and many times the damage goes unnoticed until the following spring when sections of the lawn do not green up. If you insist on “winterizing” your lawn, use a fertilizer with low nitrogen (represented by the first number in the fertilizer analysis) and high potassium (represented by the last number in the analysis). In most cases the center number (phosphorus) should also be low. But never use a high nitrogen fertilizer late in the season.
Fertilizer: Image Credit UF / IFAS
Large patch disease is another reason to avoid fertilizing after September, particularly with a high nitrogen fertilizer. Too much nitrogen at the wrong time promotes a common lawn disease called large patch, formerly known as brown patch. This disease is caused by the fungus Rhizoctonia. Large patch functions as a pathogen in our lawns during the cooler weather of fall and spring. Applying a high nitrogen fertilizer when large patch is active can be like applying gasoline to a fire, allowing this lawn disease to rage out of control.
In order for the fertilizer to do any good at all for the lawn, it needs to be applied while the grass is actively growing, when the grass can readily take it in. After the lawn is dormant and when the soil temperature is cooler, much of the fertilizer that could have benefited the grass is wasted.
by Matthew Orwat | Oct 6, 2015
Lawn Burweed, Soliva Sessilis, Closeup – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org, Create Commons License
On this bright and sunny early fall morning I was thinking about all of the great gardening opportunities the cooler fall weather is bringing us in the Florida Panhandle. However, my thoughts drifted to the annoyances that the gardeners find when trying to enjoy their lawn or garden.
On the top of my list is stepping into a patch of burweed, which is in the sunflower family and is also known as spurweed. The leaves are opposite along the stem and sometimes resemble parsley. The main ways which burweed can irk the casual gardener are sticking to socks, sneaking in with the dog, or littering flower beds with its nuisance. It can also hide in the house and reappear when shoes are removed. This causes pain in both the foot and the ear.
Aside from herbicides, maintaining a healthy vigorous lawn will prevent weeds from taking over. If you lawn is reasonably healthy and only a few instances of this weed exist, try to mechanically remove them and encourage the lawn to outgrow them.
If cultural methods aren’t sufficient, science has given us several options to control this irksome pest. A widely used pre-emergence product for burweed control is isoxaben, which is sold under the brand name of Gallery as well as others. It prevents the weed from emerging from the ground when it germinates and can be used on St. augustine, centipede, bahia and zoysia lawns, as well as ornamental shrub beds. In northwest Florida, this herbicide needs to be applied in October for best results.
Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License
Herbicides which contain the active ingredients dicamba, 2,4-D or atrazine are good at controlling burweed as a post emergence control when applied from December through early March. Be careful to use reduced rates on centipede and St. augustine lawns, and never use more than the labeled rate. Later applications have less effect on burweed because as it matures it is harder to control. Additionally the burs, once present on the lawn, are hard to remove. As the daytime temperatures get a few degrees over 80, some of these herbicides may cause lawn damage so immediate application is advised. Try to keep the spray residue outside of the root zone of desirable plants to avoid injury and always follow label directions. Be aware that burweed reproduces by seed, so mowing it down will only increase the problem by burying the seed for fall germination.
The active ingredients mentioned above are present in a variety of ‘trade name’ products* available from your local garden center, farm supply or CO-OP. I hope all the northwest Florida lawns prevent burweed so that the spring lawns will be burweed free. Happy Gardening!
| Common Name |
Manufacturer / Distributor |
Brand Names |
Type |
| Atrazine |
Many |
Many |
Pre and Post Emergent |
| 2,4-D +
MCPP + dicamba (3 way combined herbicide) |
Bayer, + others |
Many |
Post-Emergent |
| Isoxaben |
Dow, Others |
Gallery, others are now on the market |
Pre-Emergent |
*Table reproduced from sections of the 2012 version of University of Florida’s Pest Control Guide for Turf Grass Managers.
by Matt Lollar | Sep 23, 2015
Armyworms come in a wide range of colors and sizes. A few of the prominent species living in Florida are beet, southern, and fall armyworms. And the term “living” is not an exaggeration, because Florida is one of the lucky states where it is warm enough for armyworms to overwinter. They are the snowbirds that never leave!
Armyworm damage on a lawn. Credit: Purdue University
Armyworms are notorious for unanticipated invasions. They feed on most turfgrass species and most vegetable crops, but they prefer grassy vegetable crops such as corn. Armyworms feed in large groups and their feeding has been described as “ground moving” in lawns. They feed during cooler times of the day (morning and evening) and they roll up and rest under the vegetative canopy (in the thatch layer in turf and in the base of leaves in vegetables) during the heat of the day.
Armyworms are difficult to control because of their spontaneity. However, in the lawn they hide in the thatch during the heat of the day. Over watering and fertilization can increase the amount of thatch. It is important to follow UF/IFAS guidelines for home lawn management. A good weed control program can also help to deter armyworms, because weeds serve as an alternate food source.
Numerous chemical control options are available, but softer chemicals such as horticultural oils and insecticides containing the bacteria Bacillus thuringiensis are recommended as a first line of defense. Insecticides should be applied in the morning or evening during feeding time. For additional control strategies and basic information please visit the UF/IFAS Armyworm Publication Page.
Armyworm feeding on a young corn plant. Credit: University of Illinois
by Sheila Dunning | Sep 16, 2015
“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.
For information and the submission form go to:
Sample Submission Guide
For more information on the disease go to:
Take-All-Root-Rot
