Brits wear a frown when the lawn goes golden brown - but it’s stronger than they think

• Nearly one in six people believe a lawn will die within just a week without watering, but established grass will survive four to six parched weeks by becoming dormant
• Millions of households are spending more than they need to because they don’t reuse ‘free’ grey water on their gardens
• Just eight per cent of people know how much water all the different plants in their gardens need to thrive
• Thames Water is encouraging customers to use water wisely, especially during this hot weather

Brits don’t know how much water is needed to keep their lawns and plants alive despite their reputation for being green fingered, new research(1) from Thames Water reveals.

More than a quarter (29 per cent) of people have no idea how long a lawn can survive without watering. One in six people (16 per cent) believe a lawn would die within just a week with a further 17 per cent thinking it would last one to two weeks. However, established lawns are remarkably resilient. In hot weather with absolutely no water, grass will protect itself by becoming dormant for four to six weeks and then recover when the rain returns.

The research also found many people mistakenly judge a lawn’s health by its colour alone. More than half (57 per cent) believe they can tell whether a lawn is dead simply by looking at it. However, brown or golden grass is often dormant rather than dead as it conserves energy until conditions improve. Despite this, almost four in 10 people (39 per cent) believe a brown lawn is dead, while nine per cent think a golden lawn will never regain its green colour.

One in twenty (five per cent) people water their lawn it at the hottest times of the day, even in a heat wave, between midday and 4pm. Experts recommend watering gardens in the early morning or late evening, when cooler temperatures allow water to be absorbed into the soil and reduce waste through evaporation and runoff.

Millions of people are not reusing so called ‘grey water,’ wastewater from sinks, showers, baths, which could save them money and conserve water.  Almost two thirds (60 per cent) of garden owners have never reused bath water on the garden and 67 per cent have never used a bucket to capture any shower water to reuse. Over half (53 per cent) have never reused their washing up water, which could be used to water plants in their garden.  Almost a third (30 per cent) don’t reuse the water from a paddling pool on their garden.

Gardening experts support the careful use of grey water during dry weather. Soil and compost naturally help filter many soaps and detergents, and trials by the Royal Horticultural Society(2) found that using grey water on border perennials and sub-shrubs over several weeks had no significant impact on plant health.

Martin Padley, Water Director at Thames Water, said: “Many people are surprised to learn just how resilient their lawns can be. Grass can turn brown or golden during hot, dry weather, but that doesn’t mean it’s dead. In many cases it’s simply dormant and will recover when the rain returns.

“During warmer weather, demand for water increases significantly and we are asking customers to use water wisely, especially outdoors. Small changes such as collecting water while waiting for a shower to warm up, reusing paddling pool water on the garden, or using a watering can instead of a hose, can make a real difference and help protect precious water resources during the summer months.”

Many gardeners are uncertain about the needs of the plants they grow. One in six (17 per cent)  have no idea how much water their plants need or how often they should be watered. One in ten (10 per cent) gardeners only know the watering requirements for 25 per cent or less of the plants in their garden, while a further 12 per cent know the watering needs of less than half the plants. Despite Britain's reputation as a nation of keen gardeners, just eight per cent of people say they know how much water all the different plants in their garden need to thrive.

ENDS

Note to editors: 

1  Research conducted by Opinium, amongst a representative sample of 2,000 UK adults, data collected between 3-7 July 2026. Sample weighted to be nationally representative.  

2  What is grey water: expert RHS advice on using grey water in gardens / RHS