For a state that receives around 60” of rainfall a year, it is sure dry in Florida right now! In the Panhandle, the majority of our annual rainfall occurs in in bunches during winter and early spring via near-weekly cold fronts, in the mid-summer as a result of afternoon thunderstorms, and periodically in late summer/early fall if a tropical system crosses our path. Mixed in, however, are two distinct, historically dry periods: the first one in April through mid-May (contrary to popular myth, if we have May flowers, they’re gonna have to make it without April showers) and the second right now in September and October. The prolonged second dry period that we’re experiencing now makes it difficult to manage the mostly unirrigated, low-input turfgrass common in rural Panhandle lawns and pastures. It is critical to enter these expected droughts with healthy turf and remembering to employ 3 simple management tips when it quits raining (although you should follow them year-round ideally) can greatly increase your turf’s resiliency!
Unirrigated Centipdedegrass turf showing drought stress- Photo courtesy of the author.
Water Wisely – The average Florida turfgrass requires ¾-1” of water per week and we generally achieve that through rainfall. However, in our droughty months, supplemental irrigation can be a lawn saver, particularly in high traffic or more stressed areas of the yard. I realize that many of you, myself included, maintain large lawns without irrigation systems and it’s impossible to keep all your lawn well-watered during drought, but you can maintain the areas around your home, hardscapes and landscaped beds with the highest impact/visibility nicely! In these areas, put down no more than ¾” of water per irrigation event, a ballpark number that ordinarily allows the turf root zone to become saturated. Measuring your sprinkler’s water output is easily done by setting several straight-sided cans (tuna or cat food containers work great) under the sprinkler and timing how long it takes to achieve 3/4”. You might be surprised how much water you waste by leaving a sprinkler running for an hour or more!
Apply Herbicides Appropriately – Herbicides are a great item to have in the turf care toolbox, but if used incorrectly can be a waste of time and money at best, harmful to your turf at worst! Once turf and associated weeds become drought stressed (turning bluish gray, obvious wilting, leaves curling, etc.), it is too late for weed control with herbicides. There are a couple of reasons for this. First, when plants get stressed, they slow or stop their growth and focus on survival. This survival response prevents herbicides from being taken up properly and ultimately causes ineffectual weed control. Also, many herbicides specifically state on the product label that they should not be applied during certain conditions (drought, temperatures above 85-90 degrees, etc.). It is critical that one adhere to these label directions as applying the incorrect product in hot and dry conditions can cause volatility, drift to non-target plants, and in some cases, toxicity to turf you’re treating in. When it’s droughty like it is now, leave the herbicides in the chemical shed to prevent wasting your time and money and potentially damaging non-target plants!
Unirrigated Centipedegrass turf showing drought stress – photo courtesy of the author
Raise that Deck – Finally, one of the most important turf management strategies during an extended drought is to reduce mowing and raise your mower’s cutting height when/if you do mow. As mentioned above, plants are already stressed during a drought and physically chopping off a chunk of the turf plant stresses it further, causing an energy-intensive wound response when the plant is actively conserving resources for survival. Therefore, if you just HAVE to mow, raise the cutting height as high as possible to make the smallest injury possible on the grass and keep your mower blades sharp to ensure a clean cut, which will heal easier and require a smaller energy response from the plant.
During droughts like the one we’re currently in, there isn’t one silver bullet to keep your non-irrigated turf looking good. However, there are several strategies you can use throughout the year to get your lawn through dry times. Remember to water ¾”-1” per week when you can, where you can. Before you water, calibrate your sprinkler to ensure you put out enough water and don’t waste your time and inflate your utility bill by putting out too much! Reduce or eliminate use of herbicides as they are ineffective during stress periods and can harm your turfgrass. Finally, reduce or eliminate mowing and if you must mow, raise the deck! If you have any questions about getting your turf through the drought or other horticultural or agronomic topics, please contact your local UF/IFAS Extension Office!
Last week at the Panhandle Fruit and Vegetable Conference, Dr. Ali Sarkhosh presented on growing pomegranate in Florida. The pomegranate (Punica granatum) is native to central Asia. The fruit made its way to North America in the 16th century. Given their origin, it makes sense that fruit quality is best in regions with cool winters and hot, dry summers (Mediterranean climate). In the United States, the majority of pomegranates are grown in California. However, the University of Florida, with the help of Dr. Sarkhosh, is conducting research trials to find out which varieties do best in our state.
In the wild, pomegranate plants are dense, bushy shrubs growing between 6-12 feet tall with thorny branches. In the garden, they can be trained as small single trunk trees from 12-20 feet tall or as slightly shorter multi-trunk (3 to 5 trunks) trees. Pomegranate plants have beautiful flowers and can be utilized as ornamentals that also bear fruit. In fact, there are a number of varieties on the market for their aesthetics alone. Pomegranate leaves are glossy, dark green, and small. Blooms range from orange to red (about 2 inches in diameter) with crinkled petals and lots of stamens. The fruit can be yellow, deep red, or any color in between depending on variety. The fruit are round with a diameter from 2 to 5 inches.
Fruit, aril, and juice characteristics of four pomegranate cultivars grown in Florida; fruit harvested in August 2018. a) ‘Vkusnyi’, b) ‘Crab’, c) ‘Mack Glass’, d) ‘Ever Sweet’. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
A common commercial variety, ‘Wonderful’, is widely grown in California but does not perform well in Florida’s hot and humid climate. Cultivars that have performed well in Florida include: ‘Vkusnyi’; ‘Crab’; ‘Mack Glass’; and ‘Ever Sweet’. Pomegranates are adapted to many soil types from sands to clays, however yields are lower on sandy soils and fruit color is poor on clay soils. They produce best on well-drained soils with a pH range from 5.5 to 7.0. The plants should be irrigated every 7 to 10 days if a significant rain event doesn’t occur. Flavor and fruit quality are increased when irrigation is gradually reduced during fruit maturation. Pomegranates are tolerant of some flooding, but sudden changes to irrigation amounts or timing may cause fruit to split.
Two pomegranate training systems: single trunk on the left and multi-trunk on the right. Photo Credit: Ali Sarkhosh, University of Florida/IFAS
Pomegranates establish best when planted in late winter or early spring (February – March). If you plan to grow them as a hedge (shrub form), space plants 6 to 9 feet apart to allow for suckers to fill the void between plants. If you plan to plant a single tree or a few trees then space the plants at least 15 feet apart. If a tree form is desired, then suckers will need to be removed frequently. Some fruit will need to be thinned each year to reduce the chances of branches breaking from heavy fruit weight.
Anthracnose caused by Colletotrichum sp. to pomegranate fruit. Photo Credit: Gary Vallad, University of Florida/IFAS
Anthracnose is the most common disease of pomegranates. Symptoms include small, circular, reddish-brown spots (0.25 inch diameter) on leaves, stems, flowers, and fruit. Copper fungicide applications can greatly reduce disease damage. Common insects include scales and mites. Sulfur dust can be used for mite control and horticultural oil can be used to control scales.
Weeds identification and management is still one of the most common questions we receive at the local UF IFAS Extension office. Learn about the chamberbitter weed that can grow in turf and ornamental beds and the multi faceted approach that is necessary for management In the Garden with Beth Bolles, UF IFAS Extension Escambia County.
Seldom do we find the answer to a problem as being easy. More often, a difficult and complicated answer is what’s needed. However, the solution to a healthy lawn rebound may be found simply by adjusting your mower height and mowing schedule.
Mowing strategy is an important variable that keeps a lawn healthy and flourishing, no matter the species or cultivar of grass. Mowing too high can lead to an undesirable look and cause unwanted thatch buildup, which can create a favorable environment for pests and diseases. Mowing too low can weaken the root system causing thinning, which allows space for weeds to invade. Another problem with mowing too low is that it affects nutritional needs. Lawn grasses generate food for themselves through a process called photosynthesis. A healthy leaf surface area is needed to effectively accomplish this. If the lawn is mowed too low, then leaf surface area is lost. The grass can literally starve itself.
Table: Suggested mowing height for lawn grasses. Frequency of cut will vary based on species and time of year. Credit: L. E. Trenholm, J. B. Unruh & J. L. Cisar, UF/IFAS Extensio
Not all lawn grasses should be mowed at the same height, as show in the table above. Fine textured grasses like Bermuda and Zoysia matrella can be cut significantly lower than coarse textured grasses, such as Bahia or St. Augustine. Not sure of the type of lawn grass you have? Visit this site https://edis.ifas.ufl.edu/topic_book_florida_lawn_handbook_3rd_ed to review the Florida Lawn Handbook or contact your local county extension office for questions.
Mowing schedule is the other side of the coin. How often to mow ultimately depends on how fast your grass grows. By nature, Bermuda will grow quickly and Zoysia is somewhat slower growing. Regardless, summer months are when warm-season lawn grasses grow more rapidly. Historically, lawn grasses begin a dormant-slow growth stage in October and continues through March. Fertilizer schedule also plays a role in grass growth rate. So how often do you need to mow? This rate is best determined by the amount of growth since the last cutting, rather than the number of days which have elapsed. You should mow often enough so that no more than 1/4 to 1/3 of the total leaf surface is removed at any given mowing. In other words, leave twice as much leaf surface as you cut off. Remember, incremental adjustments should be made to your current practices. Never drastically change the height of the grass. If the lawn has been allowed to grow too long, you should gradually lower the mowing height on successive cuttings.
What are some other helpful tips? Always use a well-adjusted mower with a sharpened blade. You may find it easier replace your blade each year or every 2 years than periodic resharpening. Dull mower blades do a tremendous amount of damage with uneven cuts. This will cause gashes and splits in the leaf where fungal and bacterial pathogens can thrive. Never mow grass when it’s wet, either. Dry grass cuts are cleaner cuts and won’t clog the mower deck. If you have built up thatch, it’s a good idea to attach a bag to your mower that will catch clippings. These clippings will be great additions to your compost pile or to use as natural mulch. If no thatch problems exist, mowing without a bag will distribute clippings throughout the lawn, and the clippings will decompose into nutrients for the root system.
With proper mowing strategies, along with fertilizing & watering, your lawn grass can bounce back. For more information contact your local county extension office.
Information for this article provided by the UF/IFAS Extension EDIS Publication, “Mowing Your Florida Lawn”, by L. E. Trenholm, J. B. Unruh & J. L. Cisar: https://edis.ifas.ufl.edu/pdffiles/LH/LH02800.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
Horticulture Extension Agents are asked a wide variety of questions, from plant identification to erosion control, from herbicide selection to water regulation. We’re usually expected to know the answer on the spot, too. We’re also expected to write a lot and share information with the public. Well, oftentimes, those factors come together to give us writing inspiration. A challenging question leads to research and gathering of information, which leads to an answer that should be shared so others can learn from it. A recent question regarding the use and regulation of backflow preventers from a longtime gardener inspired my latest knowledge quest and what I found seemed important enough to share with other gardeners.
I would guess that backflow preventers probably aren’t a common item on people’s minds, unless you’re a plumber or in the water supply business. However, backflow prevention devices help ensure that when we turn on the tap to drink, cook, clean, flush, bathe, and yes, garden, that the water isn’t contaminated.
These larger backflow preventers are required to be installed and regularly inspected for certain plumbing systems. They usually hide under utility boxes or fake rocks. Credit: UF/IFAS.
Backflow preventers do just what their name implies, they prevent backflow. Backflow in a plumbing system happens when pressure in another part of the system drops, causing water from other locations to move in to equalize the pressure difference. This can be a problem in a potable water system when the main line loses pressure and water from a contaminated line is pulled in to the main line, potentially contaminating many users water. This can happen when a pipe breaks or during fire-fighting activities, for example. Contaminants of concern include chemical and biological agents, such as heavy metals, industrial compounds, bacteria, and pesticides.
Many of our indoor fixtures have built-in backflow preventers, such as toilets and bathtubs. Exterior backflow preventers, usually found under boxes or fake rocks near the water connection, are required for plumbing systems considered to be more of a hazard risk or where higher pressures could more easily flow back into the line. Examples of such plumbing systems include those with fire-fighting systems, hospitals, several-storied buildings, those associated with certain industrial processes, and, finally back to gardening, irrigation systems. In 1990, the Florida Building Code required that all residential irrigation systems include a backflow preventer. While the Florida Building Code also requires backflow preventers on all hose connections, i.e. spigots, many residential homeowners do not have these in place nor do water suppliers have the budgets to inspect each home’s spigots. A survey of 200 homes in the Midwest during 2002 found that 91% of homeowners did not have a backflow preventer attached to their spigots. I’m not sure north Florida would fare much better.
Gardeners should be aware of this responsibility and go ahead and install a backflow preventer on their outdoor spigots. This is especially true for those that use hose-end fertilizer or pesticide applicators, mix pesticides, or leave a pressurized hose connected to a sprinkler or other device. In addition to chemicals, all sorts of bacteria, algae, and other contaminants can grow in or enter a hose and get sucked back into the house’s line or, worse, the public supply line.
Backflow preventers are cheap and easy to install. A simple brass backflow preventer that connects between the spigot and the hose runs from $3 to $10 and will typically last for several years. You know it’s still working when water leaks out of the backflow preventer as you turn the spigot off. That’s a pretty easy and inexpensive fix to make sure the potable water source stays clean.
A simple and inexpensive hose bibb/spigot backflow preventer can help gardeners protect their potable water supply. Credit: Univ. S. Cal.
For more information on backflow prevention devices, and to keep writing ideas coming in, please contact your local UF/IFAS Extension Office.
Large patch Rhizoctonia solani (known as brown patch in cool season grasses) is a common disease of many turfgrass species. It usually occurs during the cooler months from October through May when temperatures are below 80 degrees Fahrenheit. However, signs and symptoms of large patch and other Rhizoctonia diseases can be observed throughout the summer. Less common Rhizoctonia species that occur during the summer months are Rhizoctoni zeae and Rhizoctonia oryzae. Extended periods of turf wetness from excessive rainfall or overwatering provide ideal conditions for the disease to develop and spread.
Rhizoctonia in a zoysiagrass lawn. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
This summer in Santa Rosa County, Rhizoctonia has been positively diagnosed in both St. Augustinegrass and zoysiagrass lawns and suspected in a number of centipedegrass lawns. The disease usually starts as small, yellow patches (about a foot in diameter) that turn reddish brown, brown, or straw colored as the leaves start to die. Patches often expand to several feet in diameter. It is common to see rings of yellow or brown turf with otherwise healthy turf in the center. The fungus infects portions of the blades closest to the soil, eventually killing the entire leaf. Grass blades can easily be pulled off their stems, but roots are not affected by the disease.
Rhizoctonia in a St. Augustinegrass lawn. Photo Credit: John Atkins, University of Florida/IFAS Extension – Santa Rosa County
Overwatering and excessive fertilization can both contribute to the development of Rhizoctonia disease. Improper timing of fertilizer application can also promote disease development. In the Florida Panhandle, turfgrass is actively growing from April to October. Slow-release fertilizers are recommended to allow for a more even distribution of nutrients over the course of multiple months. Recommended fertilizer rates are based on turfgrass species, geographical location, and fertilizer analysis. Please refer to the UF/IFAS Publication: “Urban Turf Fertilizer Rule for Home Lawn Fertilization” for rate recommendations.
Chart excerpted from Florida-Friendly Landscaping publication.
If large patch or another Rhizoctonia disease is confirmed in your lawn, then chemical controls are necessary to keep the disease from spreading. Fungicide products containing the active ingredients azoxystrobin, chlorothalonil, fludioxonil, flutolanil, iprodione, mancozeb, metconazole, myclobutanil, polyoxin D, propiconazole, thiophanate-methyl, thiram, triadimefon, trifloxystrobin, or triticonazole are viable options for keeping the disease from spreading. For best results, follow the fungicide label for application instructions. It’s important to not only treat the affected areas, but also the healthy turf surrounding these areas in order to keep the diseased spots from growing in size.
Unfortunately, turf diseases are often not noticed until large patches of declining and dead turf are noticed. In these cases when large dead patches exist in the lawn, it is usually necessary to resod these areas. As with most problems that arise in the landscape, good cultural practices are the most proactive way to mitigate the chances with turfgrass diseases. The UF/IFAS Florida Friendly Website provides up-to-date solutions and recommendations for caring for Florida landscapes.