After a relatively cold winter like the Florida panhandle has experienced the last couple of years, it’s always gratifying to see plants greening up in the spring. Anyone who enjoys the outdoors is likely to want to get out there and start helping things grow. That means it’s time to get the irrigation system up and running every day, right?
Probably not!
The conditions in our region can be harsh on plants. The soils are very sandy, meaning they don’t easily hold on to water or nutrients for plants to use. The weather ranges from freezing cold in the winter to sizzling hot in the summer. Rain might come down in 20-inch bursts or not at all for weeks at a time.
With all these challenges plants face, it’s very important to choose ones that can handle all that our environment throws at them. Native plants and those designated as “Florida Friendly” tend to be well suited for our location, but they still may need some care. They must be placed in the correct location in the landscape based on their needs for sunlight, water, and other factors. If you choose the right plant and place it in the right location, you’ll drastically reduce the amount of management that it needs on an ongoing basis. This includes watering.
While actively growing, plants – whether that means towering trees or low-growing grass – take up water through their roots and give some off in the form of water vapor through their leaves. If the amount of water in the soil is more than the plant is giving off, it doesn’t need more! Watering at these times can actually harm, rather than help. The roots of overwatered plants typically start to die back, which can lead to symptoms such as patchy dieback of foliage or what may look like nutrient deficiency. Overwatered areas might also see an uptick in water-loving weeds such as dollarweed, which will be difficult to control unless the area is dried out a bit.
Set irrigation systems to water early in the morning rather than at midday, and make sure they water plants, not walls.
It is tempting to think that our sandy soils drain quickly enough to make watering a constant necessity, but remember! We’ve already chosen plants that survive well in our location. Even our turfgrasses are chosen for their ability to withstand drought. There may only be three or four months out of a year that become dry enough to warrant extra irrigation at all, and even then, it’s probably less than most people expect!
For lawns, a general rule is to water only when the grass is showing signs of drought stress. Leaf blades may fold up lengthwise, the lawn’s color may become duller, and footprints in the turf persist rather than springing back. If the turf needs watering, apply ½ to ¾ inch of water per irrigation – that’s all!
Improperly calibrated irrigation systems can do more harm than good.
To figure out how much that is, set several small, empty straight-edged cans such as cat food tins or tuna cans out in the lawn. Run the irrigation for a set period of time to see how much water collects. This will also highlight any inconsistencies in watering, so you can try to adjust your irrigation system to water evenly by replacing broken nozzles and making sure the whole area is covered with no gaps or overlaps. Make sure the irrigation system is equipped with a rainfall shutoff device as well, to automatically stop watering when it rains (which it often does regularly).
Overwatered shrubs may display patchy dieback or yellowing leaves.
For landscape plants such as trees and shrubs, you may not need any supplemental irrigation at all unless there is a severe drought. Know your plants’ needs and keep an eye on the weather. Droughts, if we do have them, usually occur in the spring or fall in our area. During the summer, daily rainstorms often allow us to keep our irrigation systems off for months at a time!
Water appropriately and you may notice a reduction in your water bill, fewer plants that need to be replaced, and fewer water-loving weeds. You’ll also help the environment by reducing runoff into water bodies.
For more information on watering, contact your local Extension office. There is also a wealth of information to be found online, with resources such as the Florida Friendly Landscaping program and UF’s EDIS publications (see “Watering Your Florida Lawn”, for example). Happy watering!
The joy of being outdoors in the yard and gardens is something many of us have the opportunity to receive and appreciate. Observing nature at its best with the changes of seasons and all the activity, from birds visiting to vegetable and flower gardens to the healthy green lawns there is much to contemplate. The environment in which we live is complex and ever changing and is a critical source to our quality of life. One major source that links us all is water and the quality of it moving forward. How are we addressing changes to this important resource and the unintended consequences that can follow?
How we garden and manage the landscape at home and possibly in a business situation seems small in comparison to the number of settings out there, but if enough people work to improve water quality the positive impacts can be significant. Impervious surfaces that include paved driveways and walkways are areas that do not allow rain events or irrigation to infiltrate into the soil. Creative solutions are out there to construct pervious surfaces. Many acres of forest and wetlands have been lost to development impacting land areas like this to slow water movement allowing time for nutrients and sediment to settle and be absorbed into the soil and taken up by plants or sequestered in organic matter in the soil layers.
We often think about the larger rivers and big bodies of water that include lakes, bays, gulfs, and oceans that shoulder the large scale of human activity. It is often the smaller water sources that when combined multiple times as the tributaries involving creeks that lead to larger streams and rivers are often overlooked as having major impacts on water quality. What we can do to assist is to better manage nutrients (fertilizers and others) involving lawns, trees, and shrubs in your landscape. Work on improving soil balance through soil testing and following the recommendations to understand your soil types and plants that grow best in these settings. Contact your local University of Florida Extension office located in your county for information to assist in this important process.
A waterfront buffer zone may include a raised berm with native vegetation to slow runoff from a yard before entering the water. Photo credit: Carrie Stevenson
Creating planting buffers around creeks, ponds and lakes is critical to reducing nutrient entry links to these water sources. Care must be taken when applying nutrients that include nitrogen and phosphorus to the lawn, gardens, and other landscape areas. UF/IFAS Extension’s Florida Friendly Landscaping program recommends, if you are broadcasting fertilizer without a deflector shield, The Ring of Responsibility should extend at least 10 feet from the edge of water. Be aware that fertilizer landing on hard surface driveways and sidewalks are subject to running off with rain events and potentially entering these water sources.
There is much more information available on this topic and it is highly recommended to do a little research via the smart phone and other ways to better understand the importance of how we address water quality moving forward. Enjoy the great outdoors and appreciate all it has to offer.
It has been a hard summer climate wise and as we go into fall it is nice to start getting some relief from the heat. As the heat tones down, we are still facing a drought, which is not as severe as areas to our west but is still significant across much of the Panhandle. In our tree cover, the stress from the harsh summer this year is starting to show. You can see it in trees around the area, and it particularly seems to affect certain trees and conditions more than others. Where you are starting to see it most is in our ever-present pines, which make up the majority of our forest and tree cover in our region. If you keep a look out you may notice some pines in the areas with yellowing or brown needles or that are losing their needles. Those are clear signs of a possible bark beetle attack, which is a common issue when pines are stressed or damaged. Trees planted in the last year that are not yet fully established often show stress in a hot dry summer like this year. Even older and well-established trees in areas are showing some signs of stress from the hot dry conditions we have had this summer. Some trees are less adapted to dryer areas and when planted off site can experience more stress in dry conditions. If you look around across the Panhandle right now you can see clear signs of stress in some trees. It becomes more evident in late summer and early fall as the accumulated stressors of summer push trees into physiological conditions that cause stress responses. The big question is what to do if you notice a landscape tree that is exhibiting signs of stress, particularly drought stress.
Pine damaged by construction equipment. Barking injuries like this can encourage bark beetle attacks. Photo Credit: Ian Stone
For pines the issue is likely to be bark beetles, of which there are several types. All pine bark beetles are native to our area and the degree of damage they do varies by species and conditions. The issue with stressed trees is that most bark beetles attack those trees. When a hot dry summer occurs bark beetle activity increases as the stressed trees become less able to fend off attacks by these beetles. Unfortunately, when bark beetles attack a pine in an area the best answer is prompt removal and disposal of the infected tree material. To protect high value trees in an area where bark beetles are active there are some injection pesticides that can prevent infestation, but once a tree has been infested and begun to show symptoms little can be done to bring it back. When bark beetles attack a stressed pine, most are effectively finishing off a tree that may have died regardless. The key is to prevent them from spreading to other pines in the area or attracting them to a stressed tree in an area. With trees already stressed in our area the big prevention option is not to damage or stress any pines already on the landscape. Most pine bark beetles are attracted to trees by chemicals in pitch and resin given off by wounds or damage. Often the stress from new landscaping projects or construction around pines can cause several to succumb to bark beetles. Your best prevention is to keep equipment well away from the tree and avoid damaging or injuring the tree, especially scraping areas of bark off. Larger and older trees can be vulnerable, as well as overcrowded trees that are too dense or overtopped by others. As the cooler weather approaches bark beetle activity should decrease along with the risk of losing a pine to these pests.
Recently constructed sidewalk. Construction activities extended well into the root zone of the tree, which can cause stress and damage. Photo Credit; Ian Stone
For other trees there are additional precautions that can be taken to lessen the potential that a tree will succumb to drought and other stress. Newly planted trees or those established in the last several years are particularly at risk and should be watered regularly during this dry period. Until rains return, a good method of slowly applying water deeply to the root zone is best. Properly applied mulch can help keep the soil cooler and moist around a newly planted tree. Drip irrigation, soaker hoses, and similar methods are best, and a method that specifically applies water slowly to the tree’s root zone gives the best results. Watering your lawn does not supply sufficient water to landscape trees, especially in drought conditions. Lawn irrigation is designed to apply irrigation needed to the top portion of the soil that is available to the grass. Trees have completely different requirements and need different watering methods and amounts. If you don’t have dedicated irrigation available and you have a tree that needs water, you can use irrigation donuts or bags. These are often a good solution for a tree that needs watering temporarily. Once a tree is well established it usually can withstand even severe drought, but during the establishment phase paying attention to water needs is critical in a summer drought like we have had.
Large established trees are also not immune from the heat and dry conditions that have plagued the Panhandle this summer. Usually when conditions change these trees recover but may abort some branches or exhibit some leaf drop while stressed. Leaf drop is a phenomenon that can occur when deciduous trees are stressed. It is a method of conserving water needs by reducing the leaf demand. Usually, the tree will recover and leaf out again fine next year. A tree may abort some branches or have some branch tips die back to make it through a rough period. Trees that are overcrowded, overtopped, or have other issues are the most at risk from environmental stress. This is why good tree selection along with proper tree care and maintenance is essential. When a hot dry summer like we have had comes along well cared for and maintained trees do best. Trees that prefer more moisture like bald cypress, red maple, sycamore, and some oaks can be planted in dryer sites, but when a severe drought comes along they often don’t have the ability to handle the moisture stress that trees adapted to dryer sites can. This is why site selection is so important, it is when we have extreme conditions that off site plantings typically suffer the worst and those can be larger more established trees.
With the cool weather hopefully we will get a reprieve and some rain soon. Given that fall is one of our dryer periods it may be likely that drought conditions could persist until early winter. Good care and tree maintenance is essential to getting your trees through stressful periods like this summer. For younger trees watering and care is essential while they get established. For older established trees avoid doing any construction or other disturbing activities around them until conditions improve. If you have trees that are exhibiting signs of decline or pest attacks call your local extension office or Florida Forest Service County Forester office. With any luck, colder weather with winter rains will be here soon and trees in our area will recover over the dormant period.
Now that we are moving into warmer soil temperatures, weak areas in lawns will have a better chance of making some recovery. However, this is highly dependent on whether or not correct lawn maintenance practices are followed. These practices include fertilizing, mowing and watering correctly.
Warmer soil and correct care help improve weak lawns
Many North Florida lawns came out of winter weak and thinning this spring. In areas of the lawn where there is at least sixty percent cover of the desirable type of lawn grass, recovery is possible. But where there is less than sixty percent desirable cover, reestablishment should be considered.
Applying the correct type and amount of fertilizer will promote lawn recovery. To maintain a healthy Florida lawn, it’s critical to use a fertilizer with adequate potassium. In most cases, use a lawn fertilizer with equal amounts of nitrogen (first number) and potassium (third number) such as 8-0-8, 10-0-10, 15-2-15 or similar analysis. Phosphorus (second number) should be low or zero unless you have the results of a reliable soil test indicating that more phosphorus is needed. Err on the side of being light handed when applying fertilizer to the lawn. In North Florida, most lawns will do just fine with an application in spring no earlier than mid-April and a second application in summer no later than mid-September.
Follow these mowing practices for a healthy lawn.
Never remove more than 1/3 of the leaf blade height at any one time.
Here’s the recommended mowing height in inches for each lawn grass: bahia – 3 to 4; centipede – 1.5 to 2; standard St. Augustine cultivars – 3 to 4; dwarf St. Augustine cultivars (Captiva and Seville) – 2 to 3; zoysia cultivars suitable for home lawns- 2 to 2.5; bermuda – .5 to 1.5.
Keep mower blades sharp.
Follow these irrigation practices for a deeper rooted and drought tolerant lawn.
Turn your automatic sprinkler system off and learn to operate it manually on an as-needed basis. Your lawn needs water when leaf blades start to fold in half lengthwise or when footprints remain visible in the lawn long after being made. Irrigate when at least 30% of the lawn shows these signs of water need.
Apply ½ – ¾ inch of water when you do irrigate. Place empty, straight-sided cans in the area being irrigated to see how long it takes to reach this amount.
Irrigate during early morning for more efficient water use and to minimize lawn diseases.
Here is a link to a UF/IFAS Extension publication on Best Management Practices for a Florida lawn. http://edis.ifas.ufl.edu/ep236
Does your yard have patches of dead grass or areas that look thin and weak? The last two summers of heavy rain and the stress of December’s freezing weather have contributed to widespread outbreaks of Take-All Root Rot, a soil-inhabiting fungus Gaeumannomyces graminis var. graminis that causes yellow grass patches ranging in diameter from a few inches to more than 15 feet. The symptoms first appear in the spring, but 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. Because 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; potentially years. If the turfgrass is not stressed, leaf symptoms may never be observed. To confirm the presence of TARR, submit a sample to the UF Pathology Lab.
This disease is very difficult to control once the above-ground symptoms are observed. Measures that prevent or alleviate stress are the best methods for controlling the disease. Any stress (environmental or man-made) 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 issues. 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.
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. 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.
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 its 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 tires 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 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. But, 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.
Now that we have added another major stress with the recent heavy rain, it will be very important to continue monitoring the turf and being cautious about the cultural practices being used. Take-All Root Rot is likely to flourish. Do not encourage its development.
If the damaged areas are small, it may be possible to encourage turfgrass runners to grow back into the space. Application of 50/50 blends of sphagnum moss and course white sand can be used to top-dress the damage areas. Add no more than 1-inch of the mixture per application. After the stolons have crept into the voids and received a mowing, more top-dressing can be applied. Repeat until the grass stops growing in the fall. Fungicides applied in the spring and fall will help to keep the Gaeumannomyces graminis var. graminis suppressed.
