How Long Should You Run Your Sprinklers? (Plus the Catch Cup Test Explained)

Correct water application is vital to a healthy lawn. We will go though how long should you run your sprinklers? (Plus the Catch Cup Test Explained)

Watering your lawn isn’t about guessing or running sprinklers for a set time — it’s about how much water your sprinklers actually apply.

At Billy Goat Lawns, we regularly see lawns across Australia struggling due to incorrect watering. Too little water leads to shallow roots and stress.

The solution is simple: aim for the right water depth and measure it using a catch cup test.

In this guide, we’ll cover:

  • How long sprinklers should run
  • How much water your lawn really needs
  • How to do a catch cup test step by step
  • How to adjust sprinkler run times correctly

How Much Water Does a Lawn Need?

For most established lawns across Australia, the ideal watering target is:

  • 10–12mm of water per watering
  • Applied twice per week in warm weather
  • Reduced during cooler or rainy periods

This approach encourages:

  • Deeper, stronger root growth
  • Better drought tolerance
  • More even lawn colour
  • Fewer weeds and bare patches

Why Sprinkler Run Time Is Different for Every Lawn

There is no universal sprinkler run time.

How long sprinklers need to run depends on:

  • Sprinkler type (spray, rotor, pop-up)
  • Water pressure
  • Nozzle size
  • Spacing and overlap

One system might apply 10mm in 15 minutes, while another may take 40 minutes or more.

That’s why using a catch cup test is essential.

What Is a Catch Cup Test?

A catch cup test measures how much water your sprinklers apply over a set period of time.

You can use:

  • Measuring cups
  • Empty tuna cans
  • Any straight-sided container

This simple test removes all guesswork and lets you set accurate sprinkler run times.

How to Do a Catch Cup Test (Step by Step)

What you’ll need

  • 6–10 identical containers
  • A ruler (millimetres)
  • Your sprinkler system

Step 1: Place the cups

Spread the containers evenly across the sprinkler zone, including edges and corners.

Step 2: Run the sprinklers

Turn the sprinklers on for 20 minutes.

Step 3: Measure the water

Measure the water depth in each container in millimetres.

Step 4: Calculate the average

Add all measurements together and divide by the number of containers.

Example: Average collected in 20 minutes = 6mm

How Long Should Sprinklers Run?

Use this simple formula:

Target depth ÷ Measured depth × Run time

Example calculation

  • Target water = 12mm
  • Measured = 6mm in 20 minutes

12 ÷ 6 × 20 = 40 minutes

👉 In this case, your sprinklers should run for about 40 minutes to apply enough water.

Pro tip

If water starts to run off or pool, split watering into two shorter cycles (for example, 2 × 20 minutes).

Common Lawn Watering Mistakes

❌ Watering every day ❌ Running sprinklers for only 5–10 minutes ❌ Watering late at night ❌ Assuming all sprinklers apply the same amount of water

Correcting watering habits alone can improve lawn health within 2–3 weeks.

Final Thoughts

If there’s one key takeaway from this guide, it’s this:

Water to a depth, not a time.

By aiming for 10–12mm of water twice per week and using a catch cup test to set your sprinkler run time, you’ll take the guesswork out of lawn watering.

For wetting agents, soil conditioners, sprayers, and lawn care products to help you get the most from your watering, visit 👉 Billy Goat Lawns – Lawn Care Products

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