How to choose a garden irrigation controller

By Martin Durham

This article is part 2 of my buyers’ guide to garden irrigation controllers. In it I’ll walk you through the main things you’ll need to consider in order to choose the best garden irrigation controller for your particular circumstances.



How many different zones do you need to control?

If you want different parts of your garden to receive different amounts of water, or to receive water at different times then you have two choices:

  • Select a garden watering controller that has multi-zone capability.
  • Use one single-zone garden watering controller for each area of the garden over which you need specific control.

How much control do you want over watering start time?

The most basic controllers require you to be present to start garden watering (but shut the water off after a duration you select – so you can then leave them to it).

Some controllers contain a light sensor and can be set so that they start at sunrise and/or sunset (which are often considered to be the best times to water your garden).

Some controllers allow you to set a specific start time (either by setting an actual time or by setting them to start watering a number of hours from when they were first programmed).

How much control do you want over watering frequency?

All but the most basic controllers allow you to set how often your garden is watered. Options might include:

  • Every 6, 12, 18 or 24 hours
  • Every 2, 3, 4, 5, 6 or 7 days

How much control do you want over watering duration?

All controllers allow you to set how long your garden is watered for (usually in minutes).

More sophisticated controllers may allow you to set a different duration for different start times and or frequencies. For example, you might be able to choose to water for 1 hour in the morning and 2 hours in the evening.

What additional features do you want?

Compatibility with non-mains water supplies

Most automatic garden watering controllers are designed to connect directly to a mains water supply. Some will work in conjunction with a stored water source (such as a water butt or rainwater storage tank).

Rain sensors

Rain sensors allow your controller to alter its programming if it rains, so that you don’t over-water your plants and/or waste water.

Soil sensors

Soil sensors measure the moisture content of your soil and can then alter your controllers programming to ensure that the right amount of water is delivered at the right time.

App control

Some controllers allow you to set their programming via an app so that you can set or modify your watering schedule whenever and from wherever you want.

Weather forecast integration

Some controllers (typically those that can be controlled via an app) can modify their watering schedule according to the weather forecast.

Weather station integration

If you have a home weather station, your controller may be able to access its data and affect its watering schedule accordingly.

‘Pause’ function

A ‘pause’ function allows you to suspend your pre-selected watering schedule for a while so that you don’t get wet if your’re in the garden when a watering event has been programmed.

‘Water now’ function

A ‘water now’ function allows you to override your pre-selected watering schedule and water your garden ‘on-demand’ without having to remove your controller.

Additional hosepipe connections

If your controller if connected to your only mains water tap then additional hosepipe connections allow you to connect a hosepipe so that you can water other areas of the garden manually.

Battery level indicator

If your controller’s batteries go flat then it will stop working. A battery level indicator allows you to replace the batteries before that happens.

Battery fail protection

If your controller’s batteries go flat whilst it is watering your garden then a ‘battery fail protection’ function will automatically stop it from watering.

‘Delay start’ function

If running more than one controller from a single mains water supply there may be a pressure drop if both controllers attempt to operate simultaneously. A ‘delay start’ function is designed to stop this happening.


What next?

You’ve reached the end of part 2 of my buyers’ guide to garden irrigation controllers. Here are links to the other parts: