If you’ve just planted or rolled out a new lawn and it’s started growing, congratulations!
The hard work of getting your lawn started is done.
However, you’re probably wondering at this stage: when should I cut my new grass? Is it too early to cut it now? And how should I cut new grass?
When to cut new grass
You should mow your new grass for the first time when it reaches a height of 6 – 7cm. This should be a number of weeks, even up to a few months, after you sow your grass seeds, depending on how fast it is growing.
The reason for waiting is so that your new lawn has more time to grow properly. If it hasn’t yet reached this height, then its roots are still developing, or there could even be something stunting its growth. In this case, you’re best to wait and resolve this issue before mowing unhealthy grass.
If you’re unsure whether to cut your new grass, it’s better to be safe and let it grow a bit longer than 6-7cm.
When grass is young, you really need to avoid cutting it too early in order to maintain its long-term health. And by waiting until the grass is 6 – 7cm tall, you will give it more of a chance to thicken nicely as it continues to grow after the first cut.
Also, if you’ve planted new turf, don’t cut it if it lifts when you pull on the grass blades. This indicates that the turf has not settled into the ground and is not yet ready to mow.
How to cut new grass
Now we’ll explain some key things to consider when mowing your new lawn for the first time.
How much to take off
The first time you cut new grass, you want to take about 2cm off, leaving it at a height of about 4-5cm.
If you cut new grass too low, this could stunt its growth. You want to take off small amounts more often, rather than doing large, irregular cuts, when you’ve recently laid your turf.
After the first cut, you should wait another week or two, and then mow every few weeks.
In the longer term, you want to mow your lawn to an appropriate height for the type of grass you have. Different grasses have different tolerances for being cut short, and grow at different speeds in different climates.
Once your lawn is established, keeping your grass about 2 – 3cm tall is a good guide for most cool climate grasses seen in the UK.
Should I leave clippings in place?
When cutting new grass, you need to collect the clippings, either with the mower’s grass box or by collecting them later. If you leave clippings in place, they could block the sunlight your new grass needs to become strong and healthy.
Leaving cut grass in place could also cause a thatch overgrowth, which is best to avoid on a new lawn.
The type of law mower you use on a new lawn doesn’t matter all that much.
What does matter is the sharpness of the blades on your mower. When cutting new grass, you want to use very sharp blades.
If your lawn mower blades are blunt, they will rip the grass blades, rather than cut them. This can make it more likely for diseases to take hold, and can damage your grass significantly, especially when it is young.
When mowing new grass, you want to ensure that you mow it in a different direction to your previous cut.
For example, if you go from north to south on the first cut, you want to go east to west on the next mow, and so on.
This helps to prevent the grass blades all beginning to grow in the same direction, known as graining.