As the weather cools in Northwest Florida, we pull out jackets, enjoy cooler mornings, and watch our landscapes begin to slow down. But there is one fall chore that is easy to forget:
Change the irrigation schedule.
That sprinkler timer may still be set for July, even though your lawn is now living in October, November, or December.
Plants don’t need the same amount of water all year. As temperatures drop and days become shorter, most plants grow more slowly and use less water. Our lawns also begin slowing down and may eventually become dormant.
That means the irrigation schedule that worked during warm weather can be far too much during fall and winter.
And when it comes to irrigation, more water does not mean healthier plants.
Let the Lawn Tell You When It’s Thirsty
One of the easiest mistakes to make is watering simply because Tuesday is your scheduled irrigation day. Instead, take a look at your lawn.
UF/IFAS recommends watching turfgrass for signs that it needs water. Your lawn may be ready for irrigation when:
- Grass blades begin folding in half.
- The lawn develops a blue-gray color.
- Your footprints stay visible after you walk across the lawn.
If you don’t see these signs, you may not need to irrigate. This becomes especially important as we move into fall and winter.
During active growth, Florida lawns may require irrigation once or twice per week depending on weather, soil, and other conditions. During winter in North Florida, irrigation may be needed only once every two to three weeks. And remember—rain counts! If Mother Nature has already watered the yard, you don’t need to do it again.
Don’t Put Your Irrigation System on Autopilot
Automatic irrigation systems are convenient, but they can also waste a lot of water when we set them and forget them.
UF/IFAS recommends adjusting irrigation systems seasonally because plant water needs change throughout the year.
The EPA recommends adjusting irrigation schedules as the seasons change rather than using the same summer watering schedule all year.
Think of your irrigation controller like your home’s thermostat. You wouldn’t leave the air conditioner set for a July afternoon when it is 45 degrees outside in December. Your irrigation system deserves the same seasonal adjustment. As fall arrives, begin reducing how often your system runs. By winter, you may be able to turn off your automatic irrigation system and water only when your landscape shows signs that it needs water.
How Much Water Does a Lawn Need?
When your lawn does need water, give it enough to wet the root zone. UF/IFAS generally recommends applying about ½ to ¾ inch of water during an irrigation event. The goal isn’t to water a little bit every day. Frequent, shallow watering can encourage shallow roots. Water deeply, then allow the soil to begin to dry before watering again. This encourages deeper roots and helps your lawn handle dry weather and other stress.
An easy way to see how much your irrigation system applies is to place several straight-sided cans around the irrigation zone. Run the system and measure the water collected. This can help you determine how long your system needs to run to apply the proper amount.
Once you know that time, you don’t necessarily change the amount of water applied each time the lawn needs water. Instead, you change how often you water. That is an important difference.
Your Shrubs and Trees Aren’t Grass
Another common irrigation mistake is treating every plant in the landscape like turfgrass. Established trees and shrubs generally don’t need to be watered on the same schedule as the lawn.
UF/IFAS reports that many established, drought-tolerant landscape trees and shrubs need little or no regular irrigation. They may need supplemental water during extended drought, particularly if they are shallow-rooted, less drought-tolerant, or growing where their roots are restricted. This is why irrigation zones are important.
Ideally, turfgrass should be watered separately from shrubs, flower beds, and other landscape plants. Drip or micro irrigation can be useful in many planted beds because it delivers water closer to the root zone.
And once established, plants no longer need regular irrigation; those zones may be operated manually rather than automatically.
Fall Is the Time to Make the Change
As summer ends, take a few minutes to visit your irrigation controller. Don’t wait until January. Begin reducing irrigation as temperatures cool and plant growth slows. Pay attention to rainfall and watch your plants instead of relying only on the calendar. This is also a good time to walk through the yard while the irrigation system is running.
Look for:
- Broken sprinkler heads
- Clogged heads
- Water spraying onto sidewalks or driveways
- Sprinklers watering the street
- Leaking irrigation lines
- Areas receiving too much or too little water
EPA WaterSense recommends checking irrigation systems regularly and adjusting them as conditions change.
A sprinkler watering the driveway isn’t helping your landscape. It’s just sending water—and potentially your money—down the street.
Too Much Water Can Hurt Plants
We often worry about landscapes becoming too dry, but too much water can cause problems too. Roots need both water and oxygen. When soil stays wet for too long, roots may not get enough oxygen. This can stress plants and lead to root problems. Overwatering can also wash nutrients below the root zone or carry them away in runoff. This is one reason Florida-Friendly Landscaping™ encourages efficient irrigation. The goal isn’t simply to use less water. The goal is to use the right amount of water at the right time.
What About a Freeze?
Here is where winter watering can become a little confusing. You may have heard that watering before a freeze can help plants. There is some truth to that.
UF/IFAS notes that moist soil can absorb more heat during the day and release some of that heat at night. Making sure the soil has adequate moisture before a freeze can therefore provide some protection. But that doesn’t mean turning on your lawn sprinklers and coating plants with water during freezing weather. For the average homeowner, the important point is simple: don’t let plants go into a freeze severely drought-stressed, but don’t leave the landscape saturated either. Water, when needed, before the freezing temperatures arrive.
Container plants deserve special attention because the small amount of soil in a pot can dry faster than the ground. Move cold-sensitive containers to a protected location when possible.
Mulch Helps Too
Want to make the water already in your soil last longer? Use mulch.
Mulch around trees, shrubs and landscape beds helps reduce evaporation, moderate soil temperature and reduce weeds. A layer of mulch can help the soil stay moist longer between rainfall or irrigation events. Just remember not to pile mulch against tree trunks or shrub stems. Mulch should cover the root area—not form a volcano around the trunk.
Technology Can Help
If you have an automatic irrigation system, newer technology can make seasonal watering easier.
WaterSense-labeled controllers use local weather data to help determine when your landscape needs water. Soil-moisture-based controllers use sensors to determine whether the soil needs water. These devices can help prevent the irrigation system from running simply because the clock says it is time. Even without a smart controller, a rain shutoff device and paying attention to the weather can make a big difference.
Remember Local Watering Rules
Irrigation restrictions may limit which days or times you are allowed to water. These rules can vary by location and season. But an allowed watering day isn’t a requirement to water.
If your designated day arrives and your lawn doesn’t need water, skip it. If we received enough rain yesterday, skip it. If the soil is still moist, skip it.
Your irrigation schedule should respond to your landscape and the weather while staying within local watering restrictions.
Give Your Sprinklers a Winter Vacation
One of the best things you can do for your Northwest Florida landscape this fall is surprisingly simple:
Turn down the water.
As temperatures cool, plants grow more slowly and generally need less water. By winter, a North Florida lawn may go two to three weeks between irrigation events, and rainfall may provide all the water it needs. Established shrubs and trees may need even less supplemental irrigation.
So, before your sprinkler system wakes you up on a cold December morning by watering the driveway, take a few minutes to adjust that timer.
Watch your plants. Watch the weather. Water when the landscape needs it.
Your plants won’t miss the extra water—and neither will your water bill.
Learn More
For science-based information about landscape irrigation, visit UF/IFAS Gardening Solutions and search for irrigation or Florida-Friendly Landscaping™.
The U.S. EPA WaterSense program also provides information about efficient landscape watering, irrigation-system maintenance and WaterSense-labeled irrigation controllers.
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