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How to sow grass seed

If you're looking to create a new lawn area, grass seed is a low-cost way to get some greenery into your garden. There are a range of grass types available. Read on for step-by-step help on laying a new lawn from grass seed.

Using a garden fork to mix fresh top soil in with existing soil.Using a garden fork to mix fresh top soil in with existing soil.Using a garden fork to mix fresh top soil in with existing soil.Using a garden fork to mix fresh top soil in with existing soil.

1. Prepare the ground

Clear the ground of all stones, debris and weeds. If necessary, treat any stubborn weeds with a systemic (non-residual) weed killer – this will reduce the likelihood they'll reappear later. Dig over the entire site with a garden fork, mixing in top soil or a soil improver (if you need to) which will improve the condition of the soil. Break down any hard lumps by bashing them with the back of the fork.

If the area is prone to water-logging, work in plenty of sharp sand to help with drainage.

Add some pre-turf and seed fertiliser at about half the recommended rate and continue to take out big stones and bits of old roots. Use a garden rake to go over the ground to produce an even surface.

Person wearing walking boots walking on their heels to compress soil down.Person wearing walking boots walking on their heels to compress soil down.Person wearing walking boots walking on their heels to compress soil down.Person wearing walking boots walking on their heels to compress soil down.

2. Firm the soil down

Firm the soil down by compressing it with the heels of your boots.

Be methodical – start at one end of the patch and trample the soil in a straight line across the end of the plot, then turn around and go back. Carry on shuffling over the earth until you've covered the whole area with footprints.

Then gently rake over your footprints. Keep filling in any hollows and remove any last lumps of root and debris until the ground is as even as possible.

Keep off the area until you are ready to start sowing seed.

Person using their hand to spread grass seed evenly across a patch of soil.Person using their hand to spread grass seed evenly across a patch of soil.Person using their hand to spread grass seed evenly across a patch of soil.Person using their hand to spread grass seed evenly across a patch of soil.

3. Spread the seeds

Choose a non-windy day to sow seed, otherwise the seed will end up everywhere but where you want it!

If spreading seed by hand, tie four 1 metre bamboo canes together with garden twine to form a square. Then hold in front of you and spread a measured quantity of seed within it. This will show you how densely you need to sow the seed.

Repeat until the entire area has been covered. If using a spreader, add the seed to the spreader and cover the area until it’s covered. As with all seeds, check the packaging instructions for the recommend rate of application. Don’t be tempted to over-seed the area. This will not only cost more (in seed) but also cause the seeds to rot and die.

When you have sown over the entire area, lightly rake the surface to mix the seed into the soil. The seeds also need light to germinate so don’t rake it in too deeply. Finish the sown area by going over it methodically with a light garden roller.

Close up of a garden hose spraying water on a mist setting.Close up of a garden hose spraying water on a mist setting.Close up of a garden hose spraying water on a mist setting.Close up of a garden hose spraying water on a mist setting.

4. Water the seeds

Water in the new seeds to start the germination. If you don’t have rain within 48 hours of sowing, give the area a good soaking with a lawn sprinkler. Be careful not to wash the seeds away or create puddles. Water daily, for 7 to 10 days, until the seeds are established.

Continue regular watering of the new grass seedlings - especially if the weather is dry. While the seedlings are very tiny and delicate, water using a fine mist spray from a hose gun attachment (pictured) or sprinkler with a mist setting. As they grow stronger, water with an ordinary sprinkler.

Person using a corded lawnmower to cut the grass in a small garden.Person using a corded lawnmower to cut the grass in a small garden.Person using a corded lawnmower to cut the grass in a small garden.Person using a corded lawnmower to cut the grass in a small garden.

5. Cutting the grass

Once the grass has grown to 5cm to 8cm high, it can have its first cut. Check that the lawnmower's blade is really sharp, otherwise the shoots will tear and lift out of the ground. Set your lawnmower to its highest setting, so that you only take off the tips for the first few months and collect, and dispose of, the clippings.

The lawn will look patchy at first, but after the first cut, the grass will be encouraged to grow and fill the gaps.

As the lawn thickens up, the cutting height can gradually be lowered. Even if weeds appear, don't apply weed killer for at least the first six months after sowing. Weeds can be removed by hand whilst your new lawn establishes.

When should I plant grass seed?

For best results, lawn seed should be sown in spring (from March to May) or early autumn (September to mid October), when the soil is moist and warm.

Choosing grass seed

There’s a wide range of grass seed to choose from, according to what you want the end result to be. For a fine ornamental lawn, choose a seed mixture that doesn’t contain any coarse grasses, such as ryegrass. But for a lawn that will need to double up as a party venue or football pitch, or that will simply need to withstand regular use, the tougher and coarser grasses are a better option.

Shady and sunny areas may need different types of seed. However, the difference between two types of grass can look obvious. To make this less noticeable, you can seed the bridging area with a mixture of the two seeds.