Lawn Watering Guide: Are You Overwatering or Underwatering Your Lawn?

For many of us a deep green, healthy lawn is the place we make some of our favorite summer memories. It’s a comfortable place to sunbathe, the perfect complement to a barbecue, and the best spot for a day of yard games with family and friends. So, what does it take to grow the lush lawn we all dream of having? It starts with consistent, deep lawn watering.

Better watering habits will give your grass enough water to stay hydrated for days at a time, prevent lawn diseases, and lessen the chances of damage caused by insects. An extra challenge we face in the Intermountain West is the most common turf varieties like Kentucky bluegrass, perennial ryegrass, and turf-type tall fescue grasses are very heat sensitive. Paired with a hot, semi-arid climate and unpredictable rain, it makes sense that our lawns need proper watering to help prevent drought stress and remain healthy through the summer months.

So, what can be done to improve your lawn watering schedule? Frequency and duration are the most important variables, but there are a few other details to keep in mind. To get started, let’s look at how long you should water your lawn

How Long To Water Your Grass

The time it takes to water your lawn will depend on the lawn’s size, turf species, soil type, and climate. Generally speaking, lawns require 0.5″ – 2″ of water per week, or an average of 20 – 30 minutes of watering per zone, per session (more on this later.) Instead of light watering daily, try to water your lawn deeply and less frequently, perhaps 2 to 3 times per week for longer periods of time. This helps to deep soak the soil, causing the grass roots to reach deeper for the water they need.

The most common turf species in the Intermountain West is Kentucky Bluegrass, which needs about two inches of water per week in our hottest summer months. If you’re watering your lawn with one inch of water every three days and the lawn is still drying out between waterings, your lawn’s soil may be the reason.

Heavier clay soils have smaller spaces that drain slowly and hold water for a longer period. Adjust the sprinkler timer on clay soils so your system is watering for less time, but repeated during the same watering. For example, instead of watering for 30 minutes per sprinkler zone, set the timer to water for 15 minutes per zone on the first program and 15 minutes per zone on a second program. This will allow time for the water to soak into the root zone and eliminate the runoff that can occur if the sprinklers run for 30 minutes straight.

Coarse, sandy soil has large air spaces that let water pass quickly. Water your grass with shorter, more frequent watering if you have sandy soil. Since sandy soil drains rapidly, it’s important to build up the organic matter in the soil and increase the soils water holding capacity. Aerate the lawn annually, top dress with compost, and then rake the compost into the aeration holes. This practice will change the soil composition over time.

Another way to help improve soil fertility is to apply IFA Bountiful Earth Humate twice per year. Humate helps develop deeper, thicker root systems which absorb and hold more water, allowing for less frequent waterings over time.

When is the Best Time to Water Your Lawn?

During April and May, you may not need to water your lawn at all (depending on the temperature). As temperatures rise during the hotter summer months, you should slowly start watering your lawn more thoroughly and more frequently. Start with watering once a week, applying roughly half an inch of water. As temperatures reach above 80 degrees, start watering your lawn with one to two inches of water every three days.

The best time of day to water your lawn is early in the morning, as the sun is rising. Grass soaks up the most water early in the morning, before the soil has baked under the heat of the sun. Watering during the heat of the day (between 10am and 6pm) will lead to evaporation and wasted water. By watering at night, your grass will stay wet for a longer time which increases the likeliness of lawn diseases. Also, try to avoid watering your lawn on windy days or after a rainstorm.

How Long Does It Take Sprinklers to Spray 1″ of Water?

If you’re not sure how much time it takes for your sprinklers to spray an inch of water, you’re not alone. A good rule of thumb is that a pop-up sprinkler head will take about 20 minutes to apply half an inch of water, where an impact rotor sprinkler or gear driven sprinkler can take 40 minutes. Take this and the number of sprinkler heads applying water into consideration when deciding how long to run your sprinklers.

If you find that certain areas of your lawn don’t seem to be getting as much water as others, you can easily test to see which sprinklers are applying more water. To start, place 3 to 4 small containers (like a tuna can) on the lawn in the same zone. Then run your sprinklers for 15 minutes and measure the amount of water collected in each container. If you find they have different water levels, you’ll know that you need to adjust the sprinklers for a more even distribution.

Signs of Overwatering

Along with being soggy and unpleasant, overwatering your lawn can be as harmful as underwatering. Too much water may cause grass to develop diseases like drown root damage. Look for these signs of overwatering to see if you need to adjust your watering schedule:

  1. Weed Growth – Crabgrass and other weeds absolutely love overly wet areas. If weeds are growing quickly, overwatering may be the reason.
  2. Thatch – Too much water will cause roots to stay at the surface of the soil (instead of growing deeper), resulting in a partially decomposed layer of roots and stems called thatch.
  3. Insects – Thatch is a perfect home for insects, some of which may cause further lawn damage.
  4. Fungus – Fungi thrive in moist environments. If you notice mushrooms or other fungi growing in your lawn, reduce watering.
  5. Discoloration – Overwatering your lawn can cause the excess water to leach nutrients from the soil, causing grass blades to turn a yellow or light-green color.
  6. Runoff – Once soil is saturated with water, excess water may start to run off the lawn. Keep an eye on your irrigation system and adjust accordingly.


Signs of Underwatering

More often than not, it’s fairly easy to tell if your lawn needs more water. Dry, brittle, and/or greyish grass blades are a good sign that your grass is not receiving the amount of water it needs to stay hydrated between watering. If the lawn has spots of dry yellowed grass, apply Revive Soil Treatment during times of drought or severe heat to help the lawn retain water longer. If your lawn still seems to need more water, look for these other signs of underwatering:

  1. Dry Soil – In order for a lawn to stay hydrated, its soil must be able to retain water between watering. If the soil is dry apply less water, but more frequently.
  2. Dry Grass – As a result of dry soil, dry grass will grow significantly slower. If you’re unable to see areas of dry grass, walk across your lawn barefoot to find areas that may need more water.
  3. Ascochyta Leaf Blight – This heat and stress fungus usually appears as long, uniform stretches of yellow or brittle grass. To see if the lawn is affected by this fungus, you’ll need to look at individual grass blades. The top portion of the blade will be withered while the bottom of the blade will look green and healthy if the fungus is present.

To test your yard’s soil, stick the head of a screwdriver into the lawn. If it takes a lot of effort to push through the lawn, the soil and lawn are likely dry. Another way to tell is by walking across your lawn after watering. If you look back to see footprints, the grass is dry and needs more water.

Develop Better Lawn Watering Habits

The best way to grow a healthy lawn is simply to stay interested and involved. Check on your irrigation system monthly to ensure that all sprinkler heads are working correctly and pointed in the right direction. Gather a few tuna cans and conduct a water coverage test to see if all zones of your lawn are receiving water. This way, you’ll be more in tune with the amount of water your lawn needs throughout the seasons.

A few other good ways to ensure your entire yard is watered well are to install drip irrigation lines for trees, shrubs and gardens, as well as installing a rain gauge. Drip irrigation is a great way to be sure that smaller plants still receive a deep watering without the risk of being overwatered by a sprinkler. Likewise, a rain gauge will tell how much water the yard is receiving from rain and may even help you save on your water bill!

This year, by spending some time adjusting your watering habits you can grow the gorgeous lawn you’ve always wanted. Remember to apply IFA 4-Step Fertilizer to give your grass the nutrients it needs, and to mow regularly enough to keep grass blades at roughly three inches in length. As always, stop by your local IFA Country Store for more tips on how to grow a healthy lawn.

Information for this article was provided by Aaron Jaussi, Branch Manager, Provo IFA Country Store; Tina Potter, Utah Certified Nurseryman, Washington State Certified Nursery Professional (Lifetime), & Lawn & Garden Dept., Ogden IFA Country Store; and Ken Holt, Lawn & Garden Category Manager, IFA Country Store