Lawns tend to need a lot of water. For example, in the USA, one third of residential water use goes on lawns and landscaping.^[1] As such, they are not ideal garden features if you live where water isn't abundant or during drought. Apart from getting rid of a lawn and replacing it with plants that aren't quite as thirsty, there are a few ways you can reduce water use on a lawn. Feel free to add more ideas.

Lawn care that reduces water usage

• Choose lawn that doesn't need as much water. Lawn suited to your local area is often the best choice, as it has been grown for the conditions.
• Let the grass grow longer during the warmer and hotter weather.^[2] The longer grass allows for more moisture to remain in the soil because the taller grass shades the soil better. Longer grass copes better with being walked on too.
• Fertilize the lawn appropriately and at the right intervals. A lawn that is well fertilized can cope better with less water.^[2] In fact, a well-fed lawn can allow you to let the lawn go a little brown and still have it grow back after a decent rainfall.
• Let the grass clippings stay on the grass after mowing.^[2] The clippings break down quickly (provided you've not mowed off too much) and return nutrients to the soil and act as a temporary mulch to keep moisture in.
• Poke holes across the lawn to aerate it. Do this in early spring or autumn. It will help to increase water absorption.^[3]

Watering tips

• Water less often. This forces the grass to send its roots deeper into the soil in search of water.
• Use rainwater. As much as possible, let the rain water the lawn. Consider putting in a rainwater tank dedicated to collecting water for the lawn/garden only. Use this collected water on the lawn instead of mains water.
• Use greywater. If you can, put in a greywater system and use this water for the lawn and garden.
• Water in the early morning. This reduces the amount of evaporation.^[3] A lawn is best watered between 4AM and 10AM.^[1]
• Wster on calm days, not windy days. This reduces the evaporation and loss of water to wind.^[3]
• Don't water when it's humid or wet.^[3]
• If you use an irrigation system, have it water the soil and not the grass tops.^[3] It is more effective to keep the soil moist than to waste water on the grass blades. In fact, fifty percent of spayed water evaporates into the air.^[1]
• Train the grass to cope with less water. Only water the lawn when the blades begin to curl and when walking on it leaves footprint marks in the grass for several minutes.^[1]

An overwatered lawn is liable to disease, fungal growth and waterlogging.

Moving away from lawn

Consider removing most or all of your lawn. Lawns are a lot of work and they are thirsty. If you live in an area that does not get frequent rain, they are also somewhat of a luxury. Switch the lawn over to native grasses, a variety of drought-resistant plants and be more creative with how you design the garden space. There are many suggestions available online for changing from a lawned garden to a different style of garden, including xeriscaping.

Keep the soil healthy. A healthy soil means that the plants growing in it can tolerate less water.

Sources and citations