Fall Irrigation Changes Coming Soon!
One goal for our weekly emails is to share what we are seeing as we visit our customers’ lawn and landscapes.
So, what are we currently seeing?
Thirsty lawns and landscapes!
Since the rainy week in late August, rainfall around the Oklahoma metro area has varied. Rainfall totals over the last 30 days range from .2” inches to 1.2”. Some areas of the metro have gone 5 weeks without a .25” rainfall while others have gone 2 weeks. Typical rainfall over the last 30 days is 3.5” to 4”. So, no matter where you reside in the metro area, you are currently behind on rainfall.
All you have to do is look at any lawn, tree, shrub, groundcover, or seasonal color that isn’t irrigated to know this has not been a typical fall.
Lawns and landscapes need to be watered thoroughly in the fall to prepare them for winter.
Landscapes in poor health will be the first to suffer during stressful weather periods this coming winter.
A key to avoiding winter damage is to ensure your landscape receives adequate moisture this fall.
Pre-emergent herbicides need to be watered into the soil to be effective at stopping germination of fall and winter weeds.
Fescue lawns with the correct amount of moisture and nutrients rebound from the stress of summer and flourish in the fall.
One of the most important things you can do to have a healthy lawn and landscape are to align your watering habits with weather patterns.
Healthy irrigation is watering based on need.
Healthy irrigation is infrequent, deep watering.
Unhealthy irrigation is shallow, frequent watering.
Unhealthy irrigation is setting your irrigation in the spring on an ODD or EVEN setting and leaving it the same until you shut it off in the winter.
From lawns that are not irrigated, cores are shallow with bone dry soil. Sadly, we are finding similar cores in irrigated lawns with watering habits that are only keeping the top 1/4-1/2” moist.
From lawns that have been watered deeply over the last 6-8 weeks, we are able to easily pull deep cores that have adequate soil moisture to withstand the summer heat.
We have visited too many lawns and landscapes over the past few weeks as the heat and dryness lingered that were being watered, but yet they still showed signs of drought stress. Lawns that when you pulled a soil core, you found soil moist only for the top ¼” to ½” and completely dry soil below. Lawns with roots only ½” deep. Lawns that were dependent on daily watering.
If you want the best lawn and landscape, learning to water based on need is a critical element.
Soon temperatures will cool, day length will become shorter and shorter, and occasional rains will return… and your lawn and landscape will need less moisture. But for now, they still needing 1” of moisture per week to be healthy.
Don’t assume that because our calendar’s say it is fall, that it is okay to stop making sure your lawn and landscape sufficient moisture.
Irrigation systems with uneven water distribution issues are very noticeable after a very dry and warm September.
Follow these irrigation tips through the Fall:
Water Less Often – Don’t reduce the length of time each zone runs. Instead, water less often. Set your irrigation to run every 4 days instead of every other day.
Common question: “Should I reduce how long my system runs by 50% now?”
Answer: “No. Keep the run time the same and water less often.”
This fall instead of reducing how long a zone runs, water less often for the same amount of time you watered during the summer heat.
Water Deep Not Shallow – Deep watering is important in every season. Shallow, frequent watering promotes shallow roots, increases weed content, promotes diseases, and reduces cold hardiness. If you can get 1” of water on your lawn in a single watering without causing excessive runoff, water just one time per week. But, for most of our soils you should plan on watering ½” twice per week. It is best to saturate the soil each time you water and then allow it time to dry before watering again.
Deep soaking, infrequent watering is an important best practice in developing a healthier, deep rooted lawn even in the fall.
Know How Long You Need To Water – One piece of information that will make a big difference in your watering decisions is knowing how much water your lawn and landscape is receiving each time you run your system. Place your Hall | Stewart Rain Gauge or any small container in your lawn. Run your system through a cycle and measure the amount of water in the container. If your system puts out ½” of water, watering every 4 days this fall is perfect. If it puts out less, don’t increase how often you water, instead increase the amount of time each zone runs until your containers receive ½”.
If you have areas of your lawn that have lost color this month, checking the amount of water the area is receiving should be your first step. There is a good chance the area needs a head or nozzle adjustment.
Don’t assume that the way you have always set your irrigation is best. Do the work. Find out if your lawn is actually receiving the amount of water it needs to be healthy.
Water Based on Need – The perfect situation would be to inspect your lawn every few days and make watering decisions based on need. If the grass doesn’t spring back up after walking on it, it is time to water. If plant leaves start showing signs of wilt, it is time to water. Another easy test is to take a long screwdriver, if it slides easily into the soil you don’t need to water. Remember, plants and turf will spring back quickly from slight wilt. They don’t recover quickly from being over watered.
One of the best gifts you can give your lawn and landscape is to take a moment to inspect it each week.
Just a few minutes looking and asking yourself if everything looks healthy.
Just a few minutes of being proactive instead of reactive.
Water Based on Weather – Over the next 90 days, the average rainfall in the Oklahoma City area totals 8.5”. Your lawn and landscape will need 10-12” over the next 90 days. There is a good chance your irrigation system will be in the off position often over the next 90 days.
The Mesonet is a great weather resource for making water decisions.
This Mesonet Water Index will give you the amount of moisture in the top 2” of the soil. A reading of 1.0 tells you the soil contains all the moisture it can absorb, and any additional water will run off, a big waste of money and water.
The current average fractional water index in the metro area is .2.
A rain/freeze sensor will interrupt the watering cycle anytime it rains or if temperatures are below freezing.
A key to successful overseeding this fall is keeping the area tacky moist until the seed germinates.
Overseeding is the Exception to the Rule – If you are overseeding with fescue this fall, one of the keys to success is keeping the seeded area tacky moist until the seed germinates. Typically, this takes two weeks. We recommend setting the zones in the seeded areas to run three short cycles (3-10 minutes depending on type of head) per day: 4:00 AM, 10:00 AM, and 4:00 PM.
Tools to Improve Watering Efficiency:
Add A Rain/Freeze Sensor – A sensor will interrupt a run cycle when we have had enough rainfall. A rain/freeze sensor will pay for itself in water savings.
Add a Wi-Fi Link – Several of our customers have installed the Rainbird Wi-Fi Link and allowed us the ability to monitor their irrigation systems. Daily, we survey the Mesonet site for key weather data, make moisture need decisions and adjust systems. A rain sensor will stop a cycle, but with the Wi-Fi Link we can remotely adjust your system based on current weather data.
With the Rainbird Wi-Fi Link system, we are able to make adjustments to your system based on actual rainfall and moisture readings in your area.
The most critical step in successful fall establishment of fescue is keeping the seed moist until it germinates.
Tree Watering Tip – Trees planted in the last few years often need more water during periods of heat and drought than your irrigation system will supply. The goal is to give them 10 gallons per week. A simple way to ensure they are receiving enough water is to take a 5-gallon bucket and drill 3-5 small holes in the bottom. Place the bucket near the base of the tree, fill with water and allow the water to slowly soak into the soil. Repeat twice per week. (If you are concerned about the way it looks, use this trick overnight.)
Irrigation systems are great tools for maintaining great lawns and landscapes. But irrigation systems are not an asset when they are “set and left” with the same program in all seasons and weather conditions.
If you need help with watering issues, let us know. We would enjoy helping you manage your landscape’s water needs in the most economical and efficient ways.
Lorne Hall
Hall | Stewart Lawn + Landscape
(405)367-3873