If you are wondering when is the best time to plant grass seed and don’t know where to start in this article I’m going to be looking at the six most common mistakes beginners make when trying to sow a lawn from seed
You can avoid these mistakes to get the best results, save time and money from wasting the products that you buy
When is the best time to plant grass seed?
My first tip for seeding a lawn with is going to be around picking the best weather conditions to seed a lawn. Timing is crucial when growing grasses.
As a rule of thumb the best time to plant grass seed is in the spring and the autumn. This is because you’ve got a consistently higher temperature range, ideally above 10 degrees soil temperature. As an another bonus there is plenty of rain expected at these times of year so you wont need to water as much.
Look out for when soil temperatures are above 8-10 degrees as this temperature is what most grass seed mixes require.
The best timing depends on your location in the UK. This period usually starts from mid March onward. It finishes up in the autumn towards the end of October.
However if you do want to do some overseeding of small patches when the temperatures are colder you will need to look for a grass seed that germinate in lower temperatures. For example, our cold pro grass seed mix can germinate in temperatures of 5 degrees plus so it’s important to opt for a cold tolerant seed when seeding in cooler temps.
What depth should I plant Grass Seed?
Tip number two is around the planting depth of the lawn seed.
Some people will bury the seed under lots of topsoil and assume that the seed will germinate from that point.
This is okay for planting bulbs and other plants in the garden. But, it is not OK for grass seed.
For grass seed you want to be sowing the seed mixture within the top quarter inch of the soil bed.
If you’re establishing a completely new lawn from scratch, you will probably need to till the soil. You will also add new top soil or top dressing material.
When this is done, bury the seed slightly less than a quarter of an inch deep. Make sure they stay in the top layer of the surface.
Don’t bury the seed too deep into the soil bed. It will struggle to germinate and form a healthy root system. You’ll end up wasting your time and money.
If you are overseeding, first cut the grass on the lowest setting. Next, remove debris and thatch. Finally, apply the seed.
Covering with topdressing will improve the germination rates by locking in moisture. It will also help with leveling your lawn, providing organic matter and reducing the seeds that birds eat.
TopTip : Look for sterilised and screened soil. Sterilised soil will contain less weed seeds.
How to Water New Grass Seed
Tip number three is all about watering for new grass seeds. Most people forget this crucial step when sowing grass seed during its germination period. It needs to be kept moist, especially during the first week or two.
This doesn’t mean sitting in pools of water because that’s going to cause the seed to rot.
Conversely, it doesn’t mean keeping it bone dry. Doing so is going to slow down or even prevent the germination from happening.
Keeping the soil moist throughout the first couple of weeks is a really key step. This involves short bursts of water for maybe five minutes, a couple of times a day, throughout the germination period.
You can improve moisture retention during this period by adding a layer of soil. Topdressing will help lock in the moisture between the seed and the soil and add organic matter to the soil.
Water your new seed a couple of times a day for the first few weeks and avoid the wear and tear of foot traffic.
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Choose the Right Seed
The fourth tip is about taking the time to choose the right type of grass seed. You really want a seed that’s suitable for your lawns conditions. Let’s look at the different types of grass.
If you need a hard wearing lawn, you should choose a premium hardwearing grass seed mix. It is suitable for high foot traffic with wear and tear.
Maybe it’s in an area you’ve got to walk across to get from one part of the garden to another. You might have kids, pets and lots of foot traffic and don’t expect to have an ornamental type of lawn.
There’s also a grass seed mix designed for clay soils like the Clay King and mixes of grass for shaded areas.
Pick the seed type that’s suitable for your application! If you are unsure about your soil, you can do a soil test. This will help you find out what type of soil you have.
Another thing you might want to consider is shade. By shady, we mean things like tall trees making a canopy.Buildings or fences can also create shade whereby parts of the soil or the grass don’t get much light throughout the day.
TIP : For region-specific growing advice, see our UK growing guides
How Much Grass Seed should I apply
Tip number five is about the seed sowing rate. This means how much seed you need to put down onto your lawn to germinate effectively.
Sowing a new Lawn from Seed
If you’re sowing a lawn completely from scratch with nothing but soil, you want to target a higher seeding rate. Aim for around 50-70 grams per square meter.
Over Seed an Existing Lawn
When overseeding an existing lawn to thicken up some patches, you should choose a lower seeding rate. This seeding rate can be anywhere between 35 -70 grams per square meter.
If you are new to lawn care, I suggest using the upper range. This can help with any errors during aftercare and application. However, anywhere in this range is going to give you results.
To really thicken up the lawn, you can lean towards the higher application rates. Still, generally sticking within those two boundaries is going to give you the best results.
Anywhere above that is likely going to waste your money and potentially cause other issues with over crowding.
How to Prepare the Ground for Seeding
The last tip I wanted to discuss is ground preparation including, scarification and to core aerate the grass.
If you want to know how to plant grass seed on hard dirt and compact soiledm it will probably need core aerating first.
For most people, doing a soil test is not required and you can jump straight into seed sowing
Preparing the soil for a new lawn
Before applying the seed is the best time to kill off the weeds and lookout for any weed seeds.
Don’t put the seed down and try to kill off the weeds later. Especially in the UK, it can be difficult to target some types of weeds.
There aren’t any selective weed killers for certain weed grasses. This includes POA annua and other meadow grasses you don’t want in your lawn.
Make sure you leave enough time after applying weed killer before planting new seeds and follow the manufacturer recommendations.
Till over the soil so you’ve got a nice seed bed for the soil to sit in and refer back to the earlier tip which is sit them in the top quarter inch of the soil.
Preparing the ground for Over Seeding a Lawn
If you’re looking to overseed your lawn preparing the soil is just as key for a strong root system.
Some things to pay attention to are the amount of thatch in the lawn. You can take a sample of the lawn by cutting a little section out. Alternatively, get into the seed bed and take a look.
If you have a lot of thatch in your lawn, consider the grass blade standing upright. Imagine a layer of thatch sitting between the soil and the grass.
With the thatch layer ‘barrier’ sitting on top, seeds dropped onto your lawn for over seeding will face challenges. If they sit on that thatch layer you wont see the seeds germinate properly. They germinate better when they are sitting into the soil bed.
Scarification and using a core aerator help prepare the lawn. These processes remove thatch effectively. This is a great step to take before overseeding.
Scarification is really interesting before overseeding for another reason. It creates little furrows. This is especially true if you do two passes, one in each direction.
These little channels help the seed mixture sit in. They promote better seed to soil contact. They also offer the seed somewhere safe to grow.
The last step, which is often overlooked, is about rolling or treading in the seed. This is a great time to add organic matter to the lawn to improve seed to soil contact.
After you’ve dropped the seed down, cover with a light layer of soil or compost for organic matter. Then, you can tread or roll the lawn for great seed to soil contact.
Our summer here in Mid Wales has been just awful, I have section of garden 500 Mtr2 and have been trying to get it ready but I fear will run out of time., Half the garden has been rotovated and I’ve been told it’s not a good idea to leave it like this over winter. Is this correct?
I’d always prefer to fill open soil with grass otherwise they will fill with weeds. I’d seed in September or, you can still seed in October/November with our ColdPro grass seed mix which germinates from 5 degrees.
Hi I’m looking to replant my lawn which has been neglected and overwhelmed by weeds. I’ve applies weedkiller successfully and have raked away the dead leaves and grass, just wondering whether it’s advisable to add some organic matter before planting my grass seed and how important is it if it is? Also is topsoil recommended or does composted bark work (I’ve got some anyway)? Many thanks for a great website!!
Hi Jacob here is the process we suggest to apply your grass seed
1) Rake or scarify the lawn to remove dead grass and debris
2) Apply the seed & turf fertiliser
2) Apply the grass seed
2) If possible tread or roll down the grass seeds or lightly cover with fine compost or screened topsoil
All this can be done in the same day!