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!
It amazes me that even under flood conditions, people still water their lawns.
I’m sure you’ve seen it too – we get enough rain to cause some areas to flood and yet you see irrigation systems going full blast.
Lawn irrigation should be applied on an as needed basis. Credit: Larry Williams
We should water our lawns, landscapes and gardens on an as-needed basis. The way that some people water their lawns is as logical as saying that a pet dog needs a drink of water at 4 p.m. everyday. This is not true. When watering, we are simply replacing water that is lost. This is true when we drink water ourselves, when we provide water for a pet dog, or when we provide water for our lawns, landscapes and gardens.
An irrigation system is a great tool when used to supplement rainfall. Irrigating too much not only wastes water but it also is the cause for many lawn problems such as shallow, weak root systems, leaching of fertilizer and numerous lawn diseases. Cutting the irrigation timer to off and operating the system manually will solve many lawn problems.
Also, there are tools to prevent an irrigation system from coming on during rain or when adequate rainfall has occurred. As a matter of fact, it has been state law in Florida for every automatic irrigation system to have a rain shutoff device installed since 1991.
Florida Statutes, Chapter 373.62 – Water conservation; automatic sprinkler systems states, “Any person who purchases and installs an automatic lawn sprinkler system after May 1, 1991, shall install a rain sensor device or switch which will override the irrigation cycle of the sprinkler system when adequate rainfall has occurred,”
Rain sensors are available, inexpensive and are not difficult to install. Rain shutoff devices really do work when installed properly. If you do not feel qualified to install such a devise on an existing system, check with a reputable irrigation company.
Water only when lawn indicates that water is needed. When the grass needs water, leaf blades fold along the midrib – like a book closing, footprints remain in the lawn long after being made and the lawn turns grayish in spots, indicating it needs water.
When 30 to 40 percent of the lawn shows these signs of water need, turn the irrigation system on and let it run long enough to apply one-half to three-quarters inch of water. Don’t water again until the lawn begins to show these signs of water need. Watering this way will develop a deep-rooted lawn and landscape. Here’s a UF/IFAS Extension link with more information on lawn and landscape irrigation. https://gardeningsolutions.ifas.ufl.edu/care/irrigation
As the weather warms up, people will be outside tending to their landscapes more often. Part of that tending involves a simple thing that everyone knows plants need: water. And that is correct! Plants DO need water, and most of them need it regularly. However, even with the sandy soils in our area that drain quickly, it is possible to overwater your plants!
Overwatering can cause patchy dieback of shrubs and trees.
It is not uncommon to have a dry spell in the spring or fall in North Florida. Weeks may pass by with little or no rain, until the summer rains settle in. People may set their irrigation systems to deal with the lack of rain, but then forget to change the settings once the water isn’t needed. When plants receive too much water, we see a number of things happen. Trees and shrubs may appear to be deficient of nutrients, displaying yellowed leaves. They may die back and have a patchy appearance. Sprinklers that run constantly and splash water on leaves may increase the number of fungal diseases that plants get. Lawns that stay too damp may start seeing moisture-loving weeds such as dollarweed pop up in profusion. Luckily, we do have some guidelines for how much we should water.
For lawns or landscape plants, it is important to know what plants you are dealing with. Different plants have different needs when it comes to irrigation. Plants should be grouped by their water (and light) needs in a landscape, and irrigation zones should be set with those groupings in mind. Plants that enjoy or tolerate more water include wax myrtle, yaupon holly, swamp sunflower, swamp milkweed, pond cypress, and river birch. Others enjoy drier and well-drained soils, such as yucca, oleander, false rosemary, and turkey oak. To help determine the cultural needs of various plants, try consulting the Florida Friendly Landscaping Guide to Plant Selection and Landscape Design or the Florida Native Plant Society’s website.
When deciding whether or not to irrigate, one thing to pay attention to is the weather. All too often sprinkler systems will continue to run despite the weather – even in the middle of a thunderstorm! Install a rainfall shutoff device or make sure yours is functioning properly to avoid this. Overwatering can lead to unhealthy plants, disease issues, and weed problems.
Improperly placed or calibrated sprinklers can lead to lawn problems!
It can help to learn what a thirsty lawn looks like. Turfgrass that needs a drink will fold up its leaves, become dull bluish-green in color, and footprints will remain instead of the grass springing back. When signs of drought stress are evident, it’s time to water.
How much to water? The recommended amount is ½ to ¾ inch of water per application. Different irrigation emitters put out different amounts of water over time, so some measurement is necessary. Put out some small, straight-sided cans such as tuna or cat food cans in the area to be measured, run the irrigation for 15 minutes, and then measure how deep the water is in the cans. If you’ve collected ¼ inch of water in that time, you’ll know that you need to run the system for 30-45 minutes to give your lawn a thorough watering.
For more watering tips, there is plenty of information available. Check out these links:
Summer should be the time to relax and enjoy the fruit of all the hard work performed in the landscape over the previous winter and spring. However, there are still some essential tasks that need to be completed during the summer. Perform them in short energy bursts early in the morning or late in the evening.
1. Aerate Your Lawn
If your yard is starting to look weak and thin, even with fertilizing and proper moisture, it may need aeration. Aeration, which is creating channels into your lawn, allows water and nutrients to reach the deep roots of your grass more efficiently.
To test if you need to aerate your lawn, shovel up a patch of grass to a depth of at least four inches. If the layer of thatch is a half-inch thick or higher, your yard would benefit from aeration. There are self-drive aeration machines and tractor-pulled devices you can rent to make quick work of large areas. For smaller areas, simply punching multiple holes with a pitchfork will do the job.
2. Fertilize
Commercial landscape fertilizer applicators must obtain state certification.
Turf grass often displays a yellow color during the mid-summer rainy seasons due to the heavy rains flushing nitrogen away from plant roots. If your lawn is looking sad and yellow, chelated iron can often give a temporary green-up. Iron is not a replacement for nitrogen, but it can work well during our summer rainy season.
If you soil test revealed a potassium or magnesium deficiency, summer is a good time to make the last corrective application. Potassium (K) is an essential macronutrient. Fertilizer bags typically show the percentage of potassium in a product as the third number displayed on the front of the bag (e.g., the “8” in 16-2-8). Potassium acts as a “vitamin” for turf grass, increasing root strength, disease resistance and cold hardiness.
Magnesium (Mg), also a macronutrient, is essential for the production of chlorophyll, necessary for photosynthesis, and also plays a part in the movement of carbohydrates from leaves to other parts of the plant.
3. Don’t Mow Too Short
It’s a natural inclination to want to mow your grass as short as you can, so you have the longest time until you have to mow it again. However, giving your grass a buzz cut every time you mow can hurt your lawn over time.
While some turf grasses can be mowed relatively short, like Bermudas and some Zoysias, most grass types shouldn’t be cut shorter than two-and-one-half to four inches high. Mowing shorter than that can damage the growth point and leave it susceptible to disease and pest infestation. It can also dehydrate the grass and lead to long term damage.
5. Water Infrequently but Deeply
One common mistake made by many is watering too often and too shallow. When only given frequent shallow waterings, grass will begin to grow their roots upwards to take advantage of the small amounts of water, which makes weak and unhealthy. The grass becomes even more dependent on water and very susceptible to disease and insect attack.
Try watering only once or twice a week, but for a considerably longer time so that the water can penetrate deeper into the soil and encourage downward roots. Ideally, each irrigation zone is calibrated to determine the length of time it take to deliver ½ – ¾ inch. Then set the system to run every 3-4 days for that number of minutes. While checking the irrigation delivery system, make sure the rain shut-off device is working and set to the same ½ – ¾ inch.
6. Prevent Mosquitoes
Summer rains on a nearly daily basis lead to lots of standing water. In less than one inch of water, hundreds of mosquitoes can hatch 3 -5 days later. Not only are these blood-sucking pests annoying, but they can also transmit dangerous diseases like West Nile and Zika Virus. Even without disease, their bites are painful and irritating.
To prevent mosquitoes, make sure no standing water is allowed to remain in your yard, either in low points or in empty containers like flower pots or wheelbarrows. Any amount of stagnant water is the perfect breeding ground for mosquitoes. Take a walk around the yard, dumping out water and disturbing the oak and magnolia leaves that are acting a collection cup. Treat birdbaths and water features with floating “donuts” specifically designed to kill mosquito eggs.
While getting tasks done in quick morning trips to the yard, make sure to keep hydrated. Heat exhaustion can happen fast.
Florida is rapidly urbanizing with 1,000 people a day moving into the state. Many cities in the panhandle have experienced accelerated growth rates over the past ten years. Crestview is one of the seven areas in the state with a population growth of 19% or greater, and the only one located in the panhandle. The 2030 predictions for Florida are another 6 million people, with counties containing military personnel increasing the quickest.
All of these people need water to meet their daily living needs. The average person in the United States uses 101.5 gallons of water per day. Residential water use comprises 61% of the public supply category. This category is responsible for the largest single portion (43%) of groundwater withdrawal in Florida. The Floridan aquifer spans an area of about 100,000 square miles in the southeastern United States, including all of Florida, as well as, portions of three other states. At the current statewide population growth rate, Florida is facing a 300 million gallon per day shortfall of future water needs, possibly as early as 2030.
Turfgrass is a key landscape component and often the most commonly used single type of plant in the residential landscape. However, on a hot, sunny day in midsummer, the average lawn uses 125 gallons of water per 1,000 square feet. Although Florida has a humid climate where the precipitation rate, on average, is greater than the evapotranspiration rate, the low water-holding capacity of the soil makes irrigation necessary for the high quality landscapes desired by homeowners. But, watering the yard requires an entire household to skip a shower, not wash anything and avoid cleaning. Or, we need to find ways to use a different source of water for irrigation and conserve the potable water for the people.
While the use of reclaimed water for landscape plants has become a standard in many parts of Florida, it has limited availability in the panhandle. However, there are many ways to reduce and conserve potable water use for those with in-ground irrigation systems. First, make sure you have a functional rain shut-off device. By design it will prevent the system from running when it has recently rained. On average, the panhandle has received rain about every 4 days this year. Besides, Florida law requires a rain shut-off device for all irrigation systems, new or old.
Then, calibrate each zone to determine the length of time required to deliver ½ inch of water. This can be determined by placing 10 or more, short, straight-sided containers throughout the irrigation zone. Run the system and look at each container, measuring the depth with a ruler. Adjust the run time so the system only delivers ½ inch. Now set the clock to run 2-3 times a week for that length of time. It’s that simple. And the water savings is significant. For these and many other irrigation tips, visit askIFAS at https://edis.ifas.ufl.edu/.
