How to Start a New Lawn from Grass Seed

You've probably heard plenty of advice from your neighbors. Maybe they said starting a new lawn is hard work best left to professionals. Or that you should bite the bullet and pay for sod.

The fact is, you can save money and grow a lush, green lawn from scratch. In this article, we'll give you tips on how to transform your yard from bare ground to lush, green grass.

The Best Time of Year to Seed a Lawn

Grass seeds prefer temperatures that are consistently between 15° and 26°C to germinate. For Canada's cool-season grasses, that makes September and October the best months to start a new lawn. The warm fall temperatures and cool soil allow the seeds to store up healthy nutrients before going dormant for the winter. By spring, the new grass will be energized and ready to grow.

It's possible to seed your yard during the spring and summer months, but the grass will have to overcome additional challenges. Too much spring rain can lead to disease, and summer's long, hot days mean more frequent waterings and fighting off weeds.

Ideal Soil Conditions to Seed Your Yard

The first step in starting a new lawn is establishing a healthy environment for grass to grow. Loam or loamy soil is the perfect mix of clay, silt, and sand for growing plants. It provides water and nutrients, drains excess water, and leaves enough room for air circulation so oxygen can reach the roots of every blade.

To find out if the soil in your yard is loamy, grab a handful of dirt and pack it into a ball. Loamy soil will hold its shape and break apart easily when dry. Sandy soil will not hold its shape, and clay soil will not break apart easily when dry. If you have sandy or clay soil, the following two sections will show you how to set up a grass-friendly foundation in your lawn.

Most grasses prefer slightly acidic soil with a pH between 6.0 and 7.0. You can test the soil yourself with a home soil test kit or hire a professional. From there, you can amend your yard to improve its growing conditions. For example, soil in New Brunswick and along the B.C. coast tends to be acidic (pH under 6.0). Homeowners here can add ground limestone to the soil to raise its pH to a more grass-friendly level. If your soil is too alkaline (pH over 7.0), you can add compost, composted manure, or sulfur to lower the pH.

Note: When working with fertilizers and other lawn care products, take special care to follow all product and safety instructions.

Starting a New Lawn in Sandy Soil

Sandy soil has its benefits, like excellent drainage and air circulation, but it requires a few extra steps to grow grass from seed. If you live near a beach, follow these tips for growing lush, green grass in sandy soil:

  • Amend the soil by mixing 5 cm of organic material into the top 15 cm of soil.
  • Choose cool-season grasses like Kentucky bluegrass and fine fescues, which don't mind a little extra sand.
  • Add a loose layer of straw after seeding to prevent the seeds from washing away.
  • While the new grass is in its early stages, be vigilant about watering, which may be several times a day.
  • Once the grass reaches 5 cm, you can dial watering back to twice a week.
  • Apply fertilizer one month after seeding, then do it again the following month.
  • You can mow the grass once it reaches 7 – 8 cm, but don't rake the clippings. Instead, let them decompose where they are so the nutrients will go back into the ground.

Starting a New Lawn in Clay Soil

Clay soil does a fine job retaining water and nutrients. However, if the clay becomes compacted by heavy rain or footprints, the ground won't provide enough space or nutrition for grass roots to thrive. Here are a few tips for growing a beautiful new lawn on clay soil:

  • Amend the clay soil by working 10-15 cm of organic matter into the top 30 cm of soil.
  • You can also apply gypsum with a spreader to loosen up compacted clay.
  • Add organic matter to your lawn every year to make sure it gets the nutrients it needs.
  • Aerate your clay-soil lawn every year, too, to improve the circulation of air and water.

How Much New Grass is Required?

You don't want to run to the store in the middle of seeding your lawn. You also don't want half a bag of seed leftover when you're finished. So when you buy grass seed, check the bag to see how much it covers.

If you are not sure about the size of your lawn, use one of these methods to find out:

  • Online tools.
  • Mobile apps.
  • Measuring wheels.

What Type of Grass to Buy

Cool-season grasses like Kentucky bluegrass, fescue, and ryegrass grow well in harsh Canadian conditions. But you don't have to study grass varieties to find the right grass seed mix for your lawn. Most quality grass seed contains several varieties to give you the best results.

However, you should take note of how the sunlight hits your lawn. Is the area mostly sunny or shady? Some grass seed products are customized for sunny, dense shade, and a mix of both so you can choose the product that matches the lighting in your yard.

Cheap grass seed usually includes empty hulls, stems, weed seeds, and fillers. Check the product label to make sure the seed germination percentage is high and the weed seed content is very low. Investing a few extra dollars in quality grass now will save you time, frustration, and money later.

Use this shopping list to pick up everything you need to seed your lawn:

Preparing Soil for Seeding Your Future Lawn

You've done your research. You have all the supplies. Now it's time to get the ground ready to grow healthy grass. Here's how:

  • Dig or till the ground to a 3-inch depth.
  • Use your rake to remove clods and smooth out the surface. Remember that you're establishing a finished grade, so include any contours needed for drainage.
  • Next comes tilling. This step gets physical, so allow time for breaks along the way:

  1. Put on your safety goggles, gloves, and dust mask.
  2. Till the soil by hand or with a tiller and break up clods and compacted soil into pea-size particles.
  3. Mix in bags of weed preventing
  4. Give the soil a few days to settle after tilling. The seedbed should be firm and free of any signs of weeds.

  • Use a garden or landscaping rake to even out the surface.
  • Slope the dirt away from the house and continue removing any rocks or debris that you come across.

Applying Grass Seed on to Your Lawn

The moment you've been working toward has finally arrived. Now that the soil is ready, follow these steps to apply grass seed and care for your lawn in its early stages:

  1. Read the grass seed instructions for specific application details and the correct dial setting for your broadcast spreader.
  2. Loosen the top 3 – 5 cm of soil with a rake.
  3. Set the dial on the spreader as instructed and fill the hopper with grass seed.
  4. Push the spreader around the perimeter of your lawn first, then walk back and forth in straight lines to cover your entire yard.
  5. Overlap your passes for even coverage.
  6. Pour any unused grass seed back into the bag and sweep up any stray seeds.
  7. Lightly rake the newly seeded area to make sure the seed contacts the soil.
  8. Add a layer of granular or liquid starter fertilizer to jumpstart seed growth. (Sweep up any granules that land on your driveway or sidewalk so the fertilizer won't wash into storm drains.)
  9. Water the seeds every day to keep the soil moist for the next 1 – 2 weeks.
  10. Wait until the seedlings reach ~7.5 cm in height before you mow. Then, cut only the top one-third of the grass blades. Adjust your mower to a high setting to keep the lawn nice and thick. When you cut it too short, weeds can sneak in.
  11. Do not apply weed control until you have mowed three times.
  12. Invite the neighbors over to enjoy your beautiful new lawn.

Starting a New Lawn on a Slope or Hill

If your yard has somewhat of a steep slope, you can still grow grass from seed with a few extra steps. The biggest challenge is preventing the seeds from washing downhill when you water them or when it rains. Here's what we recommend:

  • Before you spread the seeds, mix them with soil so the seeds will be part of the dirt, not lying on top of it. Use a ratio of two parts seeds to one part soil.
  • After seeding, loosely cover the lawn with straw to hold the seeds in place. Make sure you can still see the ground beneath the straw so light and water are able to reach the grass seeds.
  • Use burlap or cheesecloth if you have a steep slope. Both materials allow light and water through, keep your seeds in place, and stop birds from eating them. 
  • Rent a grass seed slicer. About the same size as a lawnmower, a grass seed slicer cuts slits in the soil then drops seeds into them. The tiny ledges prevent the seeds from rolling downhill.

Growing Grass on Concrete

Concrete is not exactly the best foundation for growing grass, but that doesn't make it impossible. Grass is one of the best plants to grow on an old driveway or patio due to its shallow roots. The challenge is providing enough drainage so the grass doesn't become waterlogged and prone to disease.

The soil on top of the concrete will need to be at least 13 cm deep, but grass will grow deeper, stronger roots if it has 20 cm to stretch out. Deeper soil also provides more room for nutrients and drainage.

Creeping red fescue may be the best grass to grow on concrete. However, you can also get great results with other cool-season grasses, like Kentucky bluegrass, if the roots have enough room to grow.

Here are a few steps you can take to grow grass on top of concrete:

  • Wash the concrete. Concrete may be holding onto pool chemicals, antifreeze, or fungus, none of which is good for grass. Power wash or scrub the driveway or patio to keep these hazards off your new lawn.
  • Drill holes for drainage. You can also add a thin layer of gravel to help with water drainage.
  • Add a thick layer of soil mixed with organic matter, plant your grass seeds, and add fertilizer.
  • Keep a close eye on the grass to make sure the soil stays moist as the seeds germinate.
  • Feed this part of your lawn frequently using small amounts of fertilizer.