A beautiful healthy lawn needs good quality soil beneath it to help it thrive. So what makes a good quality lawn soil? This blog looks at garden soil and asks what does a lawn really need and what does it cost?
We’re incredibly lucky in the UK. Grass grows easily here. It likes our climate and for the most part, it likes our soils. However, soil types vary a lot across the UK and that can have an effect on the way grass looks and behaves.
There are many differences between lawn grass and pasture grass. Grass species, management, the way they are used and rested. One of the things that determines why lawns and pastures look so different is the way we treat the soil beneath them.
Lawn grass is completely different to pasture grass or indeed to the wheat and barley that we grow on other parts of our farms. Because lawn grasses are regularly mown and sometimes subject to heavy traffic, the plants are under a lot of stress. They need extra support. The bottom line is, that lawn grass needs suitable lawn soil if it’s going to really thrive, shrug off disease and look amazing all year round.
What makes a good lawn soil?
Low risk of compaction
The first thing to consider is soil compaction. When a lawn – or indeed a sportsfield – gets a lot of usage, the soil can easily become compacted. What that means is that all of the little tiny spaces between soil particles are squeezed out. It becomes very difficult for air and water to circulate and it’s hard for the roots to work their way through the soil. With no air, no water and no space, roots cannot function properly and the grass plants suffer.
Some types of soil are more prone to compaction than others. Very sandy soil rarely suffers compaction – but that brings other problems. More on that later. Clay or silt soils are very prone to compaction and can become almost as hard as concrete.
A good lawn soil is a mix of sandy, clay and organic particles. Together they make a strong, but well-drained soil where soil microbes and plant roots can thrive alongside each other.
Excellent water retention and good drainage
Water retention is good – to an extent. Lawns need water. Not only does it keep the plants hydrated, it dissolves plant nutrients in the soil and carries them into the plant via the roots. Too much water is a problem though. Roots need oxygen and so do the soil microbes that do so much to support plant life. If the soil is waterlogged, all of the air pockets are filled with liquid and there is not enough oxygen so support life. Lawn soil must be water retentive AND well drained.
Water the soil thoroughly and see what happens to it over the course of a day. If the water runs straight through it – the way it does when you spill water at the beach – then your soil is a bit too well drained and needs improvement. If the soil stays wet for a very long time then you need to improve the drainage. Either by installing land drains, adjusting the levels in the garden or adding grit or sharp sand to the soil.
If you are at all worried about drainage in your garden, talk to a landscape consultant who will be able to offer impartial advise. www.arbourlandscapesolutions.co.uk
Soil Acidity and Alkalinity
The ideal pH for lawn soil is 6.5 which is very slightly acidic. But in all honestly, lawn grasses are not all that fussy about acidity and alkalinity. It’s worth testing your soil pH though especially if you are hoping to grow a range of plants in your garden. If it is extremely acidic or very alkaline you may want to add either lime (to reduce acidity) or sulphur (to increase acidity) to improve the balance. Again, this is something you ought to take expert advice on. A landscape consultant or an agronomist will be able to help.
A soil pH metre measures the amount of acidity or alkalinity in the soil. They’re especially useful if you grow a wide range of flowers, fruits and vegetables. Widely available to buy online. This one is clearly not being used on a lawn – this is a very different type of grass – sugar cane.
A nice nutritious lawn soil will get your grass off to a good start. Remember though you will need to top up the nutrient levels on a regular basis. Grasses are hungry plants and as we mow them and take away their leaves we are removing most the nutrients they have absorbed from the soil.
Improving lawn soil
Lawn soil for New lawns
If you are creating a new lawn from turf or from seed, you are in the ideal position to make sure your soil is perfect for grass plants. If you are worried about the condition of your garden soil, bring in and incorporate some lawn soil to help make the ideal base for your new lawn.
Lawn soil beneath Existing lawns
It’s almost impossible to make dramatic changes to the soil beneath an established lawn – at least not without digging up the whole thing.
What you can do though is make gradual improvements to the soil over time. Regularly feeding your lawn will help keep the nutrient levels nice and high. Improve air flow and drainage by aerating 2-3 times a year, and if your soil is really sandy or heavy clay, you can topdress after hollow tine aeration. Ie brush lawn soil into the holes left by the aerator. It’s a traditional lawn maintenance technique that in my opinion deserves more attention.
The price of lawn soil
Good topsoil is hard to come by. There are a mix of different qualities on the market. Some good. Some not so good. If you have a local topsoil supplier it’s well worth paying a visit to their yard and looking at the product before you commit to buy.
If you can’t see the lawn soil before it’s delivered, then make sure you buy from a reputable supplier. Turfonline are first and foremost turf growers – so we know a lot about grass and lawn soil. We supply soil in big bags – cleaner and easier to handle than in bulk and we offer next day delivery.
Soils for wildflower lawns is very different to grass lawn soil – read more on our sister-site at www.meadowmat.com