Sowing grass seed is a great way to get a lush green lawn without the expense of buying turf. But what seed should you use? How should you prepare the ground? And perhaps most important of all – when should you sow your lawn in the first place?
That’s where we come in! We’re going to take you through everything there is to know about when to sow grass seed. So read on to get one step closer to your perfect lawn!
When is grass seed the right choice?
Grass seed can be used in two ways, either to create a lawn from scratch or to green up bare patches.
If you’re using it to create a brand new lawn, there are several advantages. It’s a lot less expensive than buying turf, and it’s easy to transport too. And if you’re laying an irregularly shaped lawn, it’s far easier to sow seed than to cut clean lines in turf.
It does, though, require good preparation and aftercare to get the right results. Your lovely flat topsoil will be just as enticing to weeds as to grass seed. And you’ll need both to prepare the ground thoroughly and to give plenty of aftercare.
If you have bare patches on your lawn, grass seed is by far the best choice to tackle them. Don’t even attempt to cut small pieces of turf. The edges will curl up and the grass will die before it’s had a chance to root.
Overseeding is easy and effective. Just spend a few moments preparing the soil, and keep it moist as the seed germinates.
When is it warm enough to sow grass seed?
You want to sow grass seed when it has the best possible chance of success. Like all seeds, grass seed needs moisture and warmth to germinate. Whenever there’s warm, wet weather, growing conditions will be good. But what does “warm” mean in the UK?
Well, grass seed requires a soil temperature of between 6 and 8 degrees Celsius to germinate. That usually means an outdoor air temperature of about 10 degrees Celsius.
In this country, that rules out winter planting. While there’s likely to be plenty of water in the ground, the soil just won’t be warm enough. And hungry birds will be grateful for the supply of seed at a time when other food sources are scarce!
From mid-spring through to mid-autumn, though, temperatures are likely to be right for successful germination. But there are other factors to bear in mind too.
Make sure there’s enough water
Warmer temperatures in summer should be great for seeds. Unfortunately, it’s also the time of year when we’re less likely to see rain.
Both seeds and young grass need plenty of water. It stimulates germination and carries nutrients around the growing grass.
For that reason, it’s best to avoid planting your lawn in the height of summer. It’s also a disadvantage of spring planting, as your grass will still be young when the weather gets hot. You’ll need to water it regularly if it doesn’t rain.
If you’re faced with a hosepipe ban, that’s going to be a lot of hard work. Not only will you have to carry a heavy watering can up and down, you’ll need to lay, move and remove boards to walk on. These are important to distribute your weight evenly and prevent damage to the young grass.
Far better to wait a few weeks to sow your grass seed. From late August onwards, the chances of rain improve. And as temperatures begin to cool, moisture will stay longer in the soil before evaporating.
Watch out for weeds
In spring, plants all around your garden are coming to life – and so are weeds. A well-prepared seed bed will be the perfect spot for them to grow.
That means that when green shoots start to appear, you may find many of them are weeds! And they can crowd out the space available for your tender grass.
Waiting to sow until late summer to early autumn will give you better results. By that time of year, the weeds will be dying back, but the ground will still be warm and moist. And if you’re lucky enough to get plenty of rain, you won’t need to water your lawn by hand.
How will you use your lawn?
It’s also worth bearing in mind how you plan to use your lawn – and when. Perhaps you’re looking forward to a summer lazing on the grass. Or maybe you have children who’ll want to play on it when the weather gets warmer.
However you’re going to use it, give your lawn as long as possible to establish itself first. That will allow the grass to get stronger and ensure it’s better able to repair any damage.
So if you want to enjoy your lawn in the summer, sowing the seed in early autumn will be ideal. The grass will stop growing over winter, then come to life again when the weather warms up in spring.
Prepare the ground properly first
Whatever time of year you seed your lawn, you’ll need to make sure you prepare the ground properly first.
If you don’t have good quality topsoil already, it’s a good idea to buy some. You’ll need a layer at least three inches deep where you’ll be planting your seeds.
If your soil is heavy clay, work in some sharp sand to improve drainage. And if your soil is very dry and sandy, add manure or other organic matter.
Next, rake over the surface so that it’s level. Then shuffle over it, keeping your weight on your heels, to compact the soil. Give it one final rake, then shuffle over it a second time. You’re now ready to sow your seed!
Of course, all this forking, raking and shuffling is energetic work. That’s another excellent reason to avoid sowing your grass seed at the height of summer. Wait until the temperatures drop slightly and you’ll find it a far more comfortable job.
Use the right grass seed for your conditions
Even the best soil preparation won’t help if your grass seed doesn’t suit your conditions.
If your lawn is in a shady area, choose a seed mix that’s specially formulated to cope with reduced light. But remember – if very little light reaches the soil, even specialist grasses will struggle. Consider whether you can increase light levels by cutting back overhanging trees or shrubs.
Remember that the amount of shade your lawn receives can vary at different times of the year. If you’re sowing your lawn in autumn, the trees may already have lost many of their leaves. They will let through more light than in the middle of summer.
Make sure you also choose a grass mix that’s suitable for the way you’ll be using your lawn. If you’ve got small children who’ll want to use it as a football pitch, choose hard-wearing varieties. Mixtures that include a high proportion of ryegrass will stand up better to wear and tear.
If your lawn is mainly decorative, you may prefer something softer and greener. Bowling green mixtures produce beautiful lawns, but they will need a lot of care. And they are vulnerable to disease.
Sow the seed at the right density
Check the instructions on your grass seed packaging carefully. Don’t be tempted to sow the seed more densely than the instructions say. Rather than getting a thicker lawn, the seeds won’t have enough room to germinate. And if the conditions are damp, there’s a risk that the roots will rot.
Tie together some garden canes to create a metre square you can lay on your lawn. Then measure out the right amount of seed mix and sprinkle it as evenly as you can over the area.
Alternatively, use a seed spreader. That will help you get consistent coverage with less effort.
Take care of your lawn after sowing
Good aftercare is essential to a great lawn.
First, protect grass seeds from hungry birds. Spread fine netting over the lawn, or hang foil containers or CDs from a piece of string. The noise and flashes will deter the birds.
It’s also important to make sure the soil doesn’t dry out. If you’ve laid your lawn in spring or autumn, the chances are that rain will do this work for you. But if there’s a dry spell, you’ll need to give the seeds a water.
Use a light spray on your hose, or a fine rose on your watering can. You don’t want to disturb the seeds with a heavy stream of water.
Ready to sow your new lawn?
We hope you’ve enjoyed our guide to when to sow grass seed. Whether you’re creating a brand new lawn or repairing bare patches, the same principles apply. Give your seeds plenty of warmth and moisture, and they’ll have the best chance of growing into strong, healthy grass.
Late summer to early autumn is the ideal time to sow grass seed. You’re likely to get warm temperatures and plenty of rain. And with the weeds dying back, you’re less likely to find unwelcome visitors amongst your new grass.
Good luck with your project, and we hope you’re soon enjoying a beautiful green lawn!