As a rule of thumb, your lawn needs moisture at a depth of approximately 2 inches from the surface. Any less than this and your grass may struggle to get sufficient water to survive. Any more and it's a waste of water as grass roots do not penetrate into the soil much deeper than this.
You can test the moisture levels in your lawn, by inserting a screwdriver or digging a small hole into the lawn feeling for moisture. If the soil is dry to touch, then your lawn needs watering. It’s a good idea to test several different areas of your lawn, as moisture levels can change wildly. You may find that areas of your lawn that are in the shade may require less water compared to areas in direct sunlight. Take these variables when watering your garden into consideration to guarantee even and healthy grass growth.
The best time to water your lawn is in the early morning – when the sun hasn’t fully risen. The temperature is lower so less water is evaporated by the sun from the soil. This means that water will penetrate down into the soil before evaporating in the midday sun. Try to resist the urge to water your lawn at night – doing so can encourage mildew, fungus and pests overnight. You should avoid watering your lawn just before you cut the grass, particularly if you are using an electric lawn mower - water and electricity don't mix. You should use a lawn mower to cut the grass when the lawn is dry to touch.
Though many sites suggest watering once a week – however, each lawn behaves differently, so there are no set rules for how often your lawn needs watering. You should always allow your lawn to partially dry before watering again.
During the warm summer months, you will need to water your lawn more regularly. The summer heat will dry the ground out faster, unlike the remaining months where it is more likely that there will be plenty of rainfall and no need for additional watering.
Different soil types require different amounts of water. Clay-based soils will need around ½ an inch of water to be fully hydrated, whereas sand-based soils will need up to a full inch due to the increased drainage.
If you find that water is running off your lawn when you water, then you will need to adapt your watering strategy. A cause of runoff can be that you’re adding more water than the soil can absorb – in this instance, lower the rate of your watering. This can be a common problem when using sprinkler systems.
Soil that’s too dry or compacted can cause runoff. A garden fork can be used to create small holes in the soil – this is called aeration. These holes allow water to penetrate deeper into the soil and help to loosen it up. This method will allow more oxygen to reach the roots which is vital for healthy growth.
Once you have aerated the soil, increase the frequency you water the lawn but decrease the amount of water used. This will allow the roots to absorb the moisture between watering so that you don’t flood the soil by accident.
Water is usually considered to be neutral, but it can be more acidic or alkaline in some areas. If your water is too acidic, it can affect the balance of calcium, magnesium and potassium in the soil. On the other hand, if it is too alkaline, it may cause calcium to build up and block the roots of your lawn.
Perform a litmus test to see what the pH of your water is, and another to find out what the pH of your soil is. Mix them together to find out what the overall pH is – between 5.5 and 6.5 is ideal.
To save water, you could collect and store rainwater runoff from your roof. This will give you a plentiful supply of water that is perfect for the garden. Always try to water early in the day and be sure not to overwater your garden.
Another helpful tip is to cut your grass frequently and leave your grass clippings on the lawn. These clippings break down and return nutrients to your lawn, they release water and nitrogen, helping to promote healthy grass growth once absorbed.
Garden hoses and sprinkler systems are used to make watering more convenient. However, during periods of extreme heat and drought, hosepipe bans may be in enforced. It is vital that you always follow these bans without exception.
Water butts are a good alternative to hose pipes and collect water when it rains. This water can then be used on your flowers, plants and garden when water is in short supply.
Using a watering can and rose is another good way to ensure that your lawn gets the correct amount of water as you can focus the pouring onto drier areas while ensuring full coverage.
How much should you water a newly seeded lawn?
For the best results, water your newly seeded lawn once or twice a day until you have mown your new lawn twice. If the climate is warm make sure to water more frequently, this will keep the top inch of soil moist. Once your lawn is settled, you can return to your usual watering routine.
How should you water a fertilised lawn?
A couple of days before adding the fertiliser, give your lawn a good drink of water. Once the grass has dried, add the fertiliser and water lightly to remove any fertiliser caught on the grass blades and flush the nutrients into the soil.
Should you water after cutting?
If your lawn needs a good drink, then do water after cutting, not before. However, if your lawn is looking healthy and happy, don’t water it now, as you might accidentally overwater it.