Garden Advice

How Long Does Grass Seed Take to Grow

Usually, under the right conditions, grass takes anywhere from 5 to 10 days to grow. However, due to different factors, the grass can sometimes take a little longer to germinate in the first place.

So, if you

  • See no sign of your new grass growing even though you’ve planted and watered seeds for several days now.
  • You have some bare patches which you’ve overseeded and want to know how long until you see results.

Then read along…

Factors that determine how long grass seed will take to grow

How does the weather affect grass growth

The first and most obvious thing that affects how fast your grass grows is the weather. You’re probably already familiar that the colder it is, the slower the grass growth will be. What you might not know, however, is that the temperature of the soil is just as important, if not more so.

Difference between soil and air temperature

Weather and soil temperatures don’t always match and that’s perfectly normal. The air in the soil is affected by the atmospheric air and is, therefore, in constant fluctuation.

The ground absorbs heat over time, then slowly releases it. That’s why the soil is still warm even when the cold days come. The weather affects the soil, which in turn will either increase or decrease the growth rate of your grass seeds.

Factors that control the temperature of the soil include soil tilth, moisture, colour, and the slope of the land. While there’s not much you can do about these factors, you can control the temperature through aeration. A soil thermometer will show whether you’re below the desired temperature, or above it.

Best soil temperature for grass growth

The best temperature for grass growth is between 6 – 35 °C (43 to 95°F). With that said:

  • cool-season grasses grow fastest in temperatures ranging from 15-24 degrees Celsius (59-75 Fahrenheit)
  • warm-season grasses grow fastest in temperatures ranging from 27-35 degrees Celsius (80-95 Fahrenheit)

The fewer temperature fluctuations there are, the better because each fluctuation will slow down the growth process. That’s you need to be sure that the weather will be nice at least two weeks after seeding.

What happens if the soil is too warm?

The popular saying “too much of a good thing” applies perfectly to this case. Your grass will experience heat stress if the weather is too warm for too long. The water in the soil will evaporate way too quickly, which in turn will deprive the seeds of much-needed moisture. The topsoil will become hard and dry, making it harder for the roots to grow. On the other hand, the seeds themselves can dry out and die.

What happens if the soil is too cold?

Water cannot move as quickly in colder soil. The colder the soil becomes, the slower the growth rate of the grass becomes. If the temperatures drop below zero, the water will freeze depriving the seeds of moisture. As a result, there is a good chance the grass will go dormant. Water is also more scarce because it falls as snow instead of liquid form. And since it’s cold, the snow won’t melt and seep into the ground.

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Growth rate according to grass seed type

Different kinds of grasses germinate and grow at different rates, even if the conditions in your lawn are as perfect as can be. Some grasses need warmer temperatures, while others require quite the opposite. One such example is:

  • Perennial Ryegrass – it only requires temperatures between 8 and 10 °C to start germinating. The weather in the UK is mostly cool, even in the warm seasons, so it’s perfect for this grass type and will ensure fast germination within 5 to 7 days.

On the other hand:

  • Carpet grasses – require air daytime temperatures ranging between 16 and 32 °C. As you might expect it will not only grow very slowly but will also have trouble germinating.

So, when searching to purchase seeds, always take into consideration the type. Some cool-season grasses that you can try include:

  • Kentucky Bluegrass: 10-20 days to germinate, and is very tolerant to cold.
  • Red Fescue: takes around 12 to 22 days to germinate.
  • Bentgrass: takes about 14 days to germinate.

How to prepare your lawn for germination

While you can’t control the weather, you can prepare your lawn for the smooth germination and growth of your grass by following the steps below:

  1. Remove the old grass along with any weeds.
  2. Fork the soil over.
  3. Tread the soil by shuffling along its surface with your heels.
  4. Level the ground by raking off bumps into hollows.
  5. Tread the soil again.
  6. Several days before you sow the seeds, rake small amounts of general fertilizer into the lawn to give the seeds a boost.
  7. Sow the seed at the right depth not more than a centimetre into the soil. Any deeper than that and the seed will not reach sunlight.

If everything goes according to plan, your grass will take about 6 to 8 weeks to grow fully.

Potential reasons why the grass is not germinating

It might seem like the conditions were perfect, but if you still fail to see results, then there might be some other explanations.

  • No comparability between soil and seed – different soils have different levels of nutrients and alkalinity and not all grass species require the exact same amounts. Some require more, some less. The point is to purchase the grass seeds right for your soil.
  • No comparability between weather and seed – if you are a novice at gardening, you might have purchased seeds that can’t germinate too well in the climate you live in. Sadly, there’s nothing you can do about that, besides buying new seeds suitable for your region.
  • Inaccurate seeding rates – it matters how many grams of seeds you spread across each square metre of your garden. If you overdo it there will be too many seeds fighting for space and nutrients, underdo it and you will get bare patches here and there. Read the package carefully and follow the instructions of how much seeds to spread over each square metre.
  • Inaccurate timing – the best time to sow grass seeds is between late summer and early to mid-autumn. That’s when the soil is still warm and damp enough, which is the basis for successful seed germination. You might have covered all the other aspects, but if you sow too close to the winter, you will see a slow growth.

Book a professional gardening service

If you find this task too daunting, consider hiring professionals. Fantastic Services works with fully equipped and highly trained gardeners. They will carry out our lawn top-dressing and re-seeding services in a stress-free manner and will restore the lush green look of your lawn. Call us today, let us know what you need and get a quote!


  • The temperature of the soil will increase or decrease the growth speed of your grass.
  • Purchase the right kind of grass seed in accordance with the soil of your property and your local climate to ensure compatibility.
  • When your lawn is properly prepared, the grass growth rate will become faster.

Imagesource: Shutterstock / Alena TS

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