Program a RainDial Timer for Overseeding

Using your RainDial Sprinkler Timer to irrigate an Overseeded Lawn

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Your watering schedule will depend on your situation.  Be sure to consult your seed provider, local nursery landscaper, or other reputable sources to determine a proper schedule. This information will explain how the Irritrol RainDial Sprinkler Timer (RD600, RD900, RD1200) can be programmed to irrigate an overseeded lawn.

You usually want to keep the seed moist during the day and give it a chance to dry out a little before nightfall.  It requires a balance between watering enough to keep the seed moist, but not too much that it pools up and floats away.  This means watering a little bit, many times throughout the day.

This article will explain how the timer can be programmed to provide a proper schedule for an overseeded lawn.  It assumes you already know the programming basics; if not, refer to this page for an excellent tutorial & videos:

(Note: The terms valves and stations are considered interchangeable.  E.g., ‘valve 1’ means the same thing as ‘station 1’.   We use valves in this description. )

An example:

Typical/Example Irrigation Scenario:

For this example, let’s say that you have stations/valves currently (summer schedule) connected as follows:

  • 1 & 2 are the front lawn (Currently part of schedule A)
  • 3 & 4 are the back lawn (Currently part of schedule A)
  • 5 and 6 are the trees and shrubs (currently Schedule B and C respectively)

As an example, let’s say you want to water your overseeded lawn for two minutes, every hour for 9 hours.  This will keep the seeds moist, but allow them to dry out a little for the night. 

Schedule B and C are currently used to water trees and shrubs.  We’re going to temporarily use those schedules to water the lawn for a couple of weeks until it is established.  Then we’ll change it back.  During this period, you can always use the timer to manually turn on the water to your trees and shrubs as needed, it just won’t be on an automatic schedule right now.   Most trees and shrubs can survive this time of year without much water anyway.  This means we can use all three schedules A, B, and C to water the lawn.

How can we get to 9 watering times during the day?

There are three schedules (A, B, and C).
Each schedule can have 3 start times (Start 1, 2, and 3).
This means we can program 3 x 3 = 9 start times.

Here’s how you’d schedule everything:

The lawn valve run times for all three schedules are set to 2 minutes. (make sure run time for your tree and shrub valves to zero or ‘off’  We don’t want them watered as part of the lawn schedule).

  • Schedule A: Start times of 8am, 9am, 10am
  • Schedule B: Start times of 11am, 12pm, 1pm
  • Schedule C: Start times of 2pm, 3pm, 4pm.
  • Set all schedules with 2 minute run times for all lawn valves.
  • Set all schedules to run every day of the week; M-Su, (or you can use a skip days value of 1)

Now your lawn will get watered for 2 minutes, every hour starting at 8 am and ending after 4 pm.  The morning hours are done by schedule A, mid-day hours by schedule B, and late day hours with Schedule C.

Of course, you can adjust this as needed for your particular lawn by changing the durations or start times, etc.

If your sprinkler timer isn’t behaving as expected, please contact for reasonable repair services and excellent customer service.