How to avoid falling victim to the biggest killer of newly turfed lawns
A beautiful new lawn from turf is one of the best investments you could make for your property. It raises kerb appeal, making your garden and property look loved, cared for and luxurious. The environmental benefits are enormous and numerous and in terms of value for money, no other form of landscaping comes close. But a newly laid lawn needs to be cared for carefully. If not, it may well fall victim to the biggest killer of newly turfed lawns. Drought.
Why new turf must never be allowed to dry out
To understand why irrigation is so important to newly laid turf, you need to understand a little bit about grass plants and the way that turf is grown and harvested.
How grass grows
A mature lawn grass plant is 70-80% water by weight. (Adult humans are around 60% water). Just like an iceberg, there is more of the plant beneath the surface than on top of it. I’m talking here about roots. Grass roots can be as much as 90 cm long and they have numerous branches and microscopic hairs on them.
To produce turf, we set seed and encourage it to grow in our prime quality soils. It’s grown out of doors in a field. No greenhouses, no polytunnels, just a field. We feed and nurture the grass so that it grows strong roots. Those roots go deep into the ground to make the most of all the nutrients that lie in the soil. The roots also search for and absorb groundwater to maintain that 70-80% water content. For without it, the plant would not be able to survive.
One of Wimborne Turf's production and harvesting fields
The grass blades grow in proportion to the roots. Roots and leaves work in perfect harmony, longer roots mean stronger grass. If the roots are weakened, grass growth slows down. The blades will never grow too big for the roots to support. The two even talk to each other using chemical messengers. When water is in short supply, the roots will send a message up to the surface and the leaves will stop growing until the soil is moist again.
Harvesting turf stresses the plants
When we harvest turf, we slice off all but the top 20mm of roots. 20mm is enough to hold the turf together without it being too heavy to handle. It also leaves enough root with enough vigour to replace what has been lost. But until that root re-grows, the grass won’t be able to sustain itself without help.
A roll of turf only has a root depth of around 20mm - most of the plants' roots have been cut off and it's vital that they are encouraged to regrow as quickly as possible
While the roots are growing, they are also sustaining the grass plants. They’re still doing their best to find water and nutrients in the soil. But they are temporarily at a disadvantage – for the grass blades are a now a little too big for the size of the roots. If you’ve ever had 10 people descend on you for dinner without prior warning and when your cupboard is almost bare, you’ll know what it’s like to be short of resources.
Newly laid turf has a lot to do. The whole plant needs to recover from being harvested, delivered and installed in a new garden. It has to do that with less than one third of its optimum root mass and if the weather is warm, there’s also the matter of water being lost to transpiration. (transpiration is the term that scientists use to describe water being lost through small holes on the surface of the leaf).
Why drought kills turf
Once you have a basic understanding of grass physiology, you can see what a struggle it is for the grass plants in your newly laid turf to survive in hot weather – let alone thrive. But it can be done. You can lay turf in warm weather and have it establish into a beautiful lawn in record time. You just need to apply enough TLC.
The roots beneath your new turf need to reach enough water to be able to support the rest of the plant. If the water lies deep beneath the surface of the soil, they won’t be able to reach it and the turf will die.
How can you prevent death from drought
Your role as keeper of the newly turfed lawn, is to make sure that those roots CAN access enough water to:
- Support the whole plant and ensure the leaves don’t wilt
- Keep enough water in the plant to support photosynthesis. Photosynthesis happens in the leaves. It takes CO2 and water and uses sunshine to combine them into sugars. Those sugars are then dissolved in water and transported to where the plant most needs energy. In this case, it’s beneath the soil where the plant is trying to repair its damaged root system.
- Start to grow deep enough to anchor the plants into the ground and access water from deep under the soil
Established lawns are very good at coping with drought but when your new turf is first laid, it can only reach water in the top 20 -25 mm of soil. If that soil is dry…well you know what will happen.
It’s imperative that you do not allow the soil to dry out at all in the first 3-4 weeks after your turf is laid.
If you want the roots to grow deeper into the soil – and trust me, you do – you MUST make sure the soil is damp for at least the top 10-15cm. Otherwise the roots have no incentive to burrow deeper.
Water your turf as soon as it is installed. Check again that first evening that the soil is still damp. You can do that by lifting the corner of one turf.
In very hot weather – over 25 degrees celcius, and particularly if it’s windy too. You will probably need to water your turf at least twice a day. Morning and Night. Check at Noon too. That turf cannot dry out or it will shrivel up and die. If it dies on your watch, that’s not the turf growers fault, neither is it the fault of the person who laid it. It’s the fault of the lawn keeper.
Watering can be a tedious job and it’s tempting to worry about the water bill too. There’s no reason why you can’t use a sprinkler on your new lawn – just make sure that the spray reaches every corner and that the edges of the lawn don’t dry out. As for the water bill – it doesn’t cost as much as you think and it’s definitely cheaper than replacing dead turf!
Rainfall is wonderful. But it’s not to be relied upon. A summer shower might not deliver enough water for your thirsty lawn. Check the soil before you decide whether to do the watering or not..
If you will be away from home, ask a neighbour to water your new lawn, or install an irrigation system. Nowadays you can buy automated systems that can be operated from your mobile phone.
After 2 weeks or so you will notice that your lawn is retaining water much better and is starting to cope on it’s own. Now you can gradually begin to reduce the frequency of watering – but you must still remain vigilant.
- Teresa Flower