How much water does your garden need?

Many people struggle to know how much to water their garden.  Do you water for 20 minutes, 40 minutes, or more?  How many days per week? And what type of sprinklers should you use?

If you have a mix of native plants and exotics, how much water does each plant type need to survive and thrive?  And how do you know if your sprinklers are applying the right amount?

It sure can be confusing, but it doesn’t have to be. There are some general rules of thumb to help you work it all out.

Generally, most plants need about 30mm of water each week to be healthy.  Natives often need less though, more like 30 mm every two weeks.  That's why they are so water efficient! 

Remember, follow the 3, 2, 1, watering guide for different plant groups:

  • Apply 10 mm of water to your lawn three times a week.
  • Apply 15 mm of water to your garden beds twice a week.
  • Apply 15 mm of water to your natives just once a week. 

So, how do you work out how long to run your irrigation to apply the right amount of water? For lawns you can work out the amount specific to your sprinklers by doing a catch can test.  For garden beds and natives, just remember that 1 mm equals 1 litre per square meter.  You need to apply 15 litres per square meter twice a week for garden beds and once a week (or less!) for natives.

Every garden is different, so follow the above guidelines, but always keep an eye on your plants and give them a drink if they look thirsty.

Wet Season and Build Up 

Use the Weather Web to help you make smart decisions about watering your garden, based on the rainfall in or nearby your suburb.  The Weather Web is a network of over 30 weather stations located on schools around the greater Darwin region providing local and current weather information.  

If you water manually or have a standard automated irrigation system, keep an eye on the Weather Web and follow the above guidelines to make smart decisions about watering your garden.  

If you have a smart irrigation controller, once you have set your weather triggers in the controller and connected it to the Weather Web, it will read the weather automatically and do all the work for you!

Dry Season

As a general guide we recommend the 3, 2, 1 watering guide in the dry season:

  • Apply 10 mm three days a week for lawn
  • Apply 15 mm two days a week for exotics such as fruit trees and palms
  • Apply 15 mm one day a week or less for native plants and trees such as acacias, grevilleas and eucalypts.

The 3, 2, 1 watering guide above will encourage your plants to grow deep root systems giving them better access to water and nutrients in the soil.  If you have been watering your garden more frequently, say twice a day, you should wean it to the 3, 2, 1 watering guide gradually. 

It’s a good idea to keep in mind that this is a guide and not a rule, as every garden is different and can require different amounts of water.  However by using this as a general guide to get started in water efficient irrigation, you can alter the amount you water by 5 minutes at a time until you reach a watering amount that you and your garden are happy with. 

You can also alter the amount you irrigate each day according to factors such as the depth of your soil, hydrozoning and the age of your plants.

Get your free Garden Tune Up

If this all sounds a bit confusing or over-whelming, or if your irrigation needs a bit of work, why not get a free Garden Tune Up.  A registered irrigation controller will audit your irrigation system and set your controller to be water efficient.  They will also give you advice to help you keep a water smart, healthy and happy garden and do small on the spot repairs up to the value of $50. 

A network of over 30 weather stations around Darwin that provides a resource of localised weather information from suburb to suburb to help you make smart decisions about efficient watering in the garden.