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What to know about laying turf on existing grass

Ask the internet “Can I lay turf on existing grass?” and the answer is generally a resounding no – but of course it’s more complex than that, so here’s what to know about laying turf on existing grass for the best results.

Why not to lay turf over old grass

First of all, a few of the reasons why NOT to lay turf over old grass. These include:

It’s harder for the turf to set down healthy roots through the old grass layer.
Once covered, old grass and vegetation can rot, cause subsidence and damage the turf’s roots.
Unwanted growth such as perennial weeds are more likely to just re-grow through the fresh turf.

Ultimately it comes down to two main reasons not to lay turf over an old lawn: it gives you less chance to fix existing problems, and it makes it less likely that the new turf will successfully lay down roots. Whichever approach you choose to take to replace an existing lawn, Proper topsoil preparations are essential to get the best results.

Reasons to lay turf on old grass

If you’re reading this article, you’re probably already thinking about reasons to lay turf on old grass, and there are a few different arguments for why you might choose to do so:

Existing grass might be very sparse and mostly bare soil showing through.
You might need a very fast green lawn for an upcoming event or social occasion.
There might be concerns (practical and financial) about disposing of the old grass if dug up.

These fall into three general categories: faster, easier and cheaper. If your garden makeover is up against it on any one of the three, then it might be enough to persuade you to lay turf on top of pre-existing turf.

Man's hands spread an artificial turf roll

How best to lay turf over grass?

If you decide you want to go ahead, it’s important to know how best to lay a new lawn over grass to give it the best chance to put down roots, grow new green grass and avoid subsidence, weeds and the use of weed killer over time.

The best chance of success is if the existing grass is very sparse – and in any case, you should prepare the soil as well as possible. Take look at our steps to prepare for laying new turf. This is a guide for laying turf on top soil, however you can appropriate some of these steps to increase that chances of your turf taking root over old grass.

Some of the main steps to follow include:

Scarify the old lawn to remove matted growth including dead grass and moss.
Rotavate the surface well to aerate compacted soil and expose bare soil for direct root contact.
Mix in a good amount of fertiliser and/or compost to improve your turf’s growth prospects.

Aftercare timeframe for turf laid over grass

Depending on the weather conditions it is important to ensure the newly laid turf is regularly watered and any debris such as leaves are removed so as to maximise sunlight to the new roots. The recommended weekly watering schedule in dry and hot weather is as follows:

Twice per 24 hours for the first week.
2-3 times per week for weeks 2 and 3.
Weekly from 3-6 weeks.

Aftercare for turf laid over grass

If you can remove the old grass at all – even just the top layer and then thoroughly rotavate the soil beneath – this will help. Follow good lawn care guidelines such as our lawn care calendar to keep your new lawn well fed and watered, and avoid heavy traffic to reduce damage as much as possible.

Any old grass you remove can be stacked away from the lawn area in an unused corner of the garden or at the back of a shrubbery, where it will rot down to create a natural fertiliser. This can then be used to feed your new turf lawn, ensuring none of the original nutrients are lost.

Where can grass be laid successfully if not on existing grass? If you are unsure what to do, get in touch with the team at Carbutts Turf, one of us will be happy to help in any way we can. We also provide a lawn laying service and can professionally install a brand new lawn for you.