When to mow and fertilise a new lawn

Knowing when to mow and fertilise your newly seeded lawn can become a bit of a conundrum, especially when summer growth can make new lawns appear established within just a few weeks.

However, whilst your lawn may appear flush with lush new grass that looks like it could withstand anything, it is important to remember that it is still establishing its root system beneath the soil.

The first mow

Whether you’ve overseeded or sown a new lawn from scratch, we can understand the itch to get mowing, as once grass starts growing – it grows fast! This can make the lawn look like it is ready to be mown. Yet, if you were to look at your lawn from a bird’s eye view – you may notice some spots you have missed, or some patches that are taking a little longer to grow. This is normal, and we recommend waiting the full 6-8 weeks after sowing your new lawn to consider mowing it. At this stage, the lawn should be established. If you find that the lawn has good coverage throughout and the sward is reaching a uniform height of around 5-7cm, it is ready for its first mow. When mowing your new lawn for the first time, make sure to mow first on the highest setting on your lawn mower, gradually dropping down to the recommended mowing height for your grass seed mixture / species. You can find the recommend mowing heights for all our mixtures here. It is vital that you stick to the recommended mowing height for your mix – some species such as perennial ryegrass will not tolerate close mowing and can be hindered by cutting too low. You should also ensure that your lawn mower has been recently serviced, and that its blades are sharp. Blunt blades can damage new grass indefinitely.

How often should you mow your lawn? and how short should you mow it?

The first fertiliser application

When your new grass grows, it will be undeniably green and lush and most likely stay this way for the first few months post-sowing. However, a lawn is a living thing and requires nutrients to keep it looking its very best. A regular fertilising routine is a good habit to get into and can also keep your lawn protected against drought in summer, and frost and winter borne diseases in the colder months. Considering many lawns in the UK go without a feed for years, a regular fertilising routine can mean as little as two applications of seasonal slow release fertiliser per year, or four applications of a seasonal quick release fertiliser per year. If you’re still pondering whether to add fertiliser to your lawn or not, read our blog on this very question.
If you have applied any type of fertiliser to your lawn prior to sowing, make sure to wait the allotted time (the instructions will suggest a waiting period) before applying any more fertiliser. You can apply a Quick Release: Spring / Summer fertiliser when the lawn is 6 - 8 weeks old or our Slow Release: Spring / Summer fertiliser. Avoid applying a Feed, Weed and Moss Killer product until the lawn is at least 6 months old – you can find out more about weed control in a newly seeded lawn here. Mowing the lawn prior to applying fertiliser will help you see where you are spreading the product. Make sure to water any fertiliser in, as it will scorch the blades if not dissolved.