When to reseed a lawn — the perfect time to sow new grass and guarantee a lush lawn this summer

If you’re hoping to kick the year off with fresh, healthy grass, you might be wondering when to reseed a lawn.

Well, knowing when to overseed a lawn is one thing, but what’s the difference? In a nutshell, overseeding involves sowing grass seed over an existing lawn to fill in any bare patches, while reseeding means removing the grass from an existing lawn and starting afresh by sowing grass seed on bare soil.

‘This is done when a lawn is severely damaged, overrun by weeds or has poor quality grass,’ explains Chris McIlroy, lawn expert at The Grass People.

So, when is the best time to reseed a lawn? You could get started as early as March — but you'll need to be aware of a few drawbacks first.

Chris McIlroy

Chris is the technical product lead and in-house lawn seed expert for The Grass People, a grass seed company that champion their expert lead advice and high-quality seed. His advice is focused on sowing, mowing, and maintaining a perfect lawn, and how to overcome any lawn issues homeowners face.

What you'll need

If you’re wondering when to reseed a lawn, you have two options — spring or autumn — but weather is the key player.

‘The best time to sow grass seed is when temperatures are consistently above 8-10°C for two weeks with no adverse weather conditions on your local weather forecast, such as frost, storms or floods,’ says Chris.

So, spring or autumn? Which is better?

When to reseed a lawn in spring

You can start thinking about reseeding your lawn as the days begin to warm in spring, but you'll need to double-check the weather forecast first — just as you would before you start cutting your grass again after winter.

'It’s important to wait until the risk of frost has passed and the soil has warmed up enough for good seed germination,' advises Cheryl Harper, managing director at Greensleeves Lawn Care.

If you're sure that the colder days are behind us, spring is the ideal time to reseed a lawn in time for summer. ‘Sowing in spring brings the perfect combination of warmth, sunshine and rainfall,’ explains Chris. 'Spring reseeding would mean your new lawn is fully established come summer.'

But there is one drawback.

Cheryl Harper

Cheryl Harper is the managing director of Greensleeves Lawn Care.

Established in 1998, Greensleeves Lawn Care is a UK-wide lawn care business with over 100 locations.

‘Be aware that weeds can be active during this season, which you may need to keep an eye on,’ Chris warns.

If you happen to miss the spring sowing window, you’ll be looking at autumn instead...

When to reseed a lawn in autumn

You can reseed a lawn in autumn, but you’ll need to act early for the best results.

In fact, autumn sowing, when timed right, is a safer bet if you’re hoping to avoid looking for ways to get rid of weeds in a lawn.

'There’s more rainfall and weeds grow less aggressively, so the new grass has less competition,’ explains Chris.

It's Cheryl's favourite time to reseed a lawn, too. 'Autumn is considered the ideal time because the soil is still warm from the summer, which promotes seed germination,' she says.

'The cooler temperatures reduce stress on the newly seeded grass, giving it plenty of time to establish before the colder winter months.'

So, now we know when to reseed a lawn! Spring or autumn are both solid options, but early autumn is ideal if you want to tackle fewer weeds and see even better germination rates.

FAQs

What months can I put grass seed down?

We've established that spring and autumn are the best seasons to reseed a lawn, but what months can we put grass seed down in general?

'March to May is a great time to put new seed down, but remember to keep it well-watered, monitor weed growth, and keep foot traffic to a minimum,' says Chris.

And, of course, early autumn is another brilliant time to sow new grass seed. 'September is the recommended month for sowing a new lawn as it brings optimal conditions for seed germination,' Chris explains.

If you're looking for other ways to revive your lawn after winter, we have a guide on that, too.