How Much Grass Seed do I Need For a New Lawn?

Hi David,

It’s great that you’re looking to start fresh with your lawn, and I can understand why you’d want to get the seeding just right. I’m going to assume that you don’t have an existing lawn of any sort given that you say you’re looking to sow a new lawn from scratch.

Regardless of the size of your lawn, you’ll generally need around 20-35 grams of seed per square metre. That would mean you’re looking at 640 to 1,120 grams of grass seed for your entire 32-square metre lawn, depending on the type of seed mix you’re using and how thick you want the coverage.

It’s better to aim for that middle ground—too little seed could lead to gaps, while too much can cause overcrowding. When grass seeds are packed too tightly, they end up competing for nutrients, water, and sunlight, which weakens the overall health of the lawn. On the flip side, a sparse sowing can leave bare patches, and weeds might take the opportunity to move in.

With that said, I wouldn’t worry too much about using too much or too little seed. It’s highly unlikely that you’ll use too much (most people would stop before putting down so much seed that you couldn’t actually distinguish them on the soil). And if you don’t use enough, you can always overseed the bare patches once the grass has started to grow and you can see what you’re working with.

On that note, if you do need to overseed (which is likely), you’d typically use about half the amount of seed you would for a new lawn, so roughly 10-15 grams per square metre. This helps fill in any thin areas without overwhelming the existing grass.

If you want to be more certain about your application rates, there are a couple of things you can do:

1. Mesure a 1-square metre area in your lawn, then weigh around 30 grams of grass seed and sprinkle the seed within this area. Going by eye, you can then sprinkle a similar quantity of seed onto the rest of your lawn, imagining it broken down into 1-square metre areas. Perhaps this isn’t precise enough for you, but I’m going to let you into a secret that should offer some relief: you don’t need to be exact with your grass seed sowing rates.

2. Buy a grass seed applicator or dispenser and use this to distribute the seed across your lawn. This is a better option than doing it by hand as it allows the seed to be distributed more evenly, reducing the likelihood of clogging in one area and sparseness in others. I’ve personally had a good experience with the Gardena Handheld Spreader (<Amazon link); you hold it in your hand and turn the lever (a bit like the old window-opening mechanisms on cars) to spread the grass seed.

I’d recommend a good quality seed blend suited for your local climate (assuming you live in the UK, go for cool-season grasses like ryes and fescues) and the specific conditions of your lawn, whether it’s shaded, gets full sun, or experiences a lot of foot traffic. Check out our guide to the best grass seed for more information.

It’s also worth thinking about the soil preparation. Well-prepped soil, free of weeds and well-aerated, will help the seeds settle in and take root properly. However, you don’t need to be extremely picky with your soil quality as grass will grow pretty much anywhere! A perfect example of this is Bradley, who runs our Turf Doctor YouTube account—he removed block pavings from his garden and sowed a lawn straight onto the existing soil (watch the video here), and now, just a few months later, he has a thick, green lawn.

Good luck with the project! If you need any more advice or help choosing the right seed, feel free to reach out.

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