Sowing Grass Seed on a Existing Lawn

Adding more lawn seed to an existing lawn is commonly known as overseeding, this garden practice is one of the key steps to achieving a lush green lawn. Sowing grass seed on an existing lawn helps to fill in dead or poor growing patches. It also helps to make your lawn greener as well as fight of those pesky weeds.

Man using seed spreader to lay new seed

Man using seed spreader to lay new seed

How to sow grass seed on an existing lawn

Step 1 – Choose the right seed

This is the most important step, get this wrong and you may end up making your lawn look worse rather than better. Different species of grass can look very different so you want to avoid mixing types if at all possible. If you are unsure a mixed seed containing a few different kinds of grass could work well as it will help blend the different grasses together. Look for a mixed seed with ryegrass and fescue.

Step 2 – Mow the lawn

Next, you will want to dig the mower out of the shed and give your grass a good chop, cut down to around 30mm. If you don’t know the exact cutting depth of your mower go for around the second or third setting up from lowest.

Step 3 – Aerate the lawn

Now you need to ger some holes in your lawn. This can be achieved manually using a fork or if you have one a purpose-built aerator will speed up the process.

Step 4 – Sow your seed

Now its time to lay down your new seed. I usually do this by hand but you can buy a seed dispenser for this job. If doing by hand get a good handful in your palm. Then slightly cup your hand and with your palm facing skywards throw the seed out in a side to side motion. This helps fan the seed out and gives a good even coverage.

Step 4 – Water

Your seed needs moisture to properly germinate, but you don’t want to get the hose straight on it. This will wash your seed away and cause it to clump together in specific spots. Instead, wait 2-3 days and if you have had no rain then water with a light misty setting.

When should I overseed?

Overseeding your lawn works best in mild yet wet conditions. So spring or autumn are perfect, these are the same times of year you should be seeding a brand new lawn too. If seeding in spring make sure the last frost has passed, the same goes for autumn but in reverse.

You can also overseed in the summer but just check the forecast first. Don’t go overseeding if we are expecting a long dry spell, I know, not much chance of that anyway!

Mowing after sowing grass seed onto existing lawn

To start with you want to leave the mower safely tucked away in the shed for at least a couple of weeks. This will give your little grass seedlings time to establish themselves before you go giving them a hair cut.

On your first cut move your mower up a height or two from your usual cutting height. This will again give the new grass time to bed in and establish strong roots before cutting.

Why overseed?

As your lawn ages, it can lose its lustre, bald patches start to creep in and the colour can fade. Adding new young grass can fix both these problems and improve the overall health of the lawn.

Overseeding also works as a great natural weed defence. Lawns with barren patches attract weeds, if you keep your lawn full of grass then there’s less space for weeds to grow, it really is as simple as that.

Hey, I'm Daniel. Having worked as a professional gardener for years as well as keeping a private allotment I decided to create this website to help spread my knowledge. I love gardening and hope to show you just how rewarding it can be!