Your new turfed or seeded lawn is growing nicely and it’s time for the first cut. Here’s my advice on mowing your new lawn for the first time.

nutrients your lawn needs

Mowing is one of the most important things you can do to help establish a new lawn. Removing the tips of the leaves encourages the plants to grow more blades. Thus resulting in a denser, more attractive sward. A nice thick sward is not only more durable, it makes it harder for unwanted plants to grow in your lawn.

Having said that, mowing mistakes can easily slow down your lawn’s development. By following my tips for mowing your lawn for the first time, you will be setting yourself up for success.

Before you start mowing your new lawn

The single most important thing you can do for your grass is to clean and sharpen the blades of your lawnmower.

Cutting the grass effectively leaves an open wound on almost every leaf. That’s unavoidable. However, each wound is a potential entry point for disease pathogens. Making sure that you cut with a clean sharp blade reduces the risk of disease. Not only that, a razor sharp blade leaves

When to mow your new lawn for the first time

Timing is crucial.

If you mow your new grass too early, you’ll put the young plants under considerable strain. Leave it too long and you risk missing the opportunity to thicken the sward while it’s still young.

When to mow a newly turfed lawn

The grass plants in turf are already reasonably mature. However, they will have lost a lot of root mass during the harvesting and re-laying process. It’s vital that those roots have started to re-grow before you start your mowing regime.

The ultimate test to find out if your newly turfed lawn is ready to mow is the tug test. Grab a handful of grass and tug on it. If you feel the earth move – that means that the turf is lifting and therefore the roots need a little longer to settle in. Leave the mower in the shed for now and try again in a few days-time.

If you do the tug test and blades of grass break off in your hand – it’s OK to give your newly turfed lawn its first cut.

When to mow a newly seeded lawn

As a rule of thumb, newly seeded lawns are ready for the first cut when the grass blades are 6-7 cm long. Any shorter and the root won’t be developed enough to support the plant as it recovers. Much longer and the fine leaved plants in your seed mix – aka the fescues and the bent grasses – will start to be outcompeted by faster growing grasses like ryegrass.

How to mow your lawn for the first time

When mowing your lawn for the first time, it’s important not to cut it too short. Just nip the tips off the grass blades and leave plenty of green leaves.

  • Make sure your mower blades are really sharp
  • Put the grass box on – you’ll need to collect the clippings
  • Double-check that the grass plants have rooted in well
  • Set the mower blades high
  • Choose a fine day when the weather is reasonably warm and the grass is dry
  • Never mow your lawn if frost is forecast
  • Aim to remove no more than a quarter of the length
  • In very dry weather, it’s advisable to water your new lawn immediately after mowing.
  • Leave 3-5 days (depending on the time of year) before the next cut

When can you start using your new lawn?

It’s ever so tempting to bring out all of the picnic rugs and toys and start using your lawn as soon as you see green shoots. That would be a big mistake.

The structure of a young grass plant is nowhere near strong enough to cope with heavy wear and tear. Grass has evolved to be walked on and eaten by animals. (This is why the actively growing cells are at the end of the roots and the crown of the plant). In the natural world, the grass blades are nibbled, and then, using nutrients supplied by the roots, they regrow. For lawn grasses, the secret to durability is to have strong enough roots to support speedy regrowth.  

Before you start subjecting your lawn to regular wear and tear, it’s important to let those roots get really well established before you start crushing the plants.

A turfed lawn can receive regular foot traffic in 3-6 months after installation. For a seeded lawn, it’s best to wait 6-9 months….even if the grass does look lovely and lush, the roots just won’t be ready.

Planning your lawncare regime for the first few weeks


Be sure to mow your new grass regularly until it’s really well established. This will encourage a nice, dense, weed-free lawn.

For your lawn, mowing is the equivalent of having a teenager come into your kitchen and eating everything in the fridge. The grass blades are the power house for the whole plant. That’s where sunlight gets turned into the energy that the roots need to grow and gather nutrients. When the food store is depleted, the plants can’t develop as they should. Which is why it’s important to not scalp a young lawn.

Mowing too short will really weaken the grass plants. Try to maintain your new lawn at a height around 5 cm for at least the first 6-9 months of its life. A fine leaved lawn comprising mainly fescues and/or bent grasses can tolerate closer mowing. Aim for 3 cm in those all-important early months.


lawn feed applicator standing on a beautiful lush green lawn

As you are mowing (and therefore removing nutrients) on a regular basis, it’s important that you make sure you replace those nutrients just as regularly.

Your lawn care regime should include regular lawn treatments and feeding. I recommend applying a pre-seeding (or pre-turfing) fertiliser 6 weeks after laying turf or sowing seed. From then on, feed every 6-8 weeks with the right lawn feed for the season.

Read more about lawn nutrition here. (I’ll also repost the link at the end of this article)

Aerating and scarifying

After 12 months, it’s a good idea to aerate your new lawn to encourage those roots to grow even deeper.  Light scarification will be in order too – but don’t set the blades too low. Don’t rush to scarify and be very gentle first time round. Especially if your lawn has been grown from seed. (You can be a bit tougher with turfed lawns). If in doubt, I’m happy to advise.

Troubleshooting on new lawns

Very occasionally, creating a new lawn doesn’t go quite to plan. Mother Nature is great, but she does like to throw in a curve ball every now and again.

Toadstools in new lawns

The most common problem I hear about in new lawns – especially newly turfed lawns, is toadstools. Mushrooms and toadstools are actually a sign of really healthy soil, but they can be a worry. Toadstools grow when healthy soil gets disturbed. This stimulates any dormant fungal spores into growth. Couple that with all the watering you’re doing to keep your plants healthy and you have the perfect growing conditions for toadstools.

The number 1 rule is not to panic. Something like 400 different types of toadstool have been identified growing in UK lawns, and so far, none of them have been poisonous. Having said that, unless you know that your toadstools are among the 400, don’t eat them.

lawn toadstools

Mowing your lawn will normally get rid of the toadstools. You may get two or three flushes of them but after that they’ll disappear of their own accord.

Why toadstools in the lawn are nothing to worry about 

Lawn diseases

We’ve spoken about toadstools. The most common lawn diseases such as fusarium patch disease are also caused by microscopic fungi. Fusarium patch disease can spread quickly and do a lot of damage in a young lawn. If you spot the early signs, please call me as soon as possible to discuss the right remedies for your lawn.

Damping off disease is unusual in recently seeded lawns, but it’s not unheard of. This particular phenomenon is usually symptomatic of problems with drainage or watering. It’s better to avoid damping off than try to cure it. So take care to get the watering right. The seedbed should never be allowed to dry out but don’t let it get soggy either. There’s not much you can do about rainfall, but if your soil was properly prepared before the seed was sown, it should be well drained.

How to prepare soil for seeding or turfing 

Weeds in new lawns

If there’s one thing Mother Nature hates it’s bare soil. Her second pet hate seems to be a mono-culture. Laying turf should suppress any annual weed seeds in the soil seed bank. With seeding however, you can expect to see a few intruders germinating alongside your grass.

Don’t panic! The grass will usually outcompete most of the weeds, and the majority of what’s left won’t tolerate the mower. Do learn to recognise the stronger, peskier weeds though, and pull them out as soon as you see them. Dandelions, for example, are easy to spot and easy to uproot in a soft seedbed. DO NOT apply herbicides to a young lawn – you’ll damage the grass. If you are at all worried, send me a picture of the offenders and I’ll advise you on what to do next.

Some useful articles on caring for a new lawn

Learn more about the nutrients your lawn needs  

Identifying lawn weeds 

Caring for a newly turfed lawn