Seeding Your Lawn: Why, When, & How To Start

The Best Time Of Year To Plant Seed

Like all vegetation, grasses have ideal planting times. The best time of year to plant grass seed will depend on your area, and whether you’re planting cool-season or warm-season grass.

Warm Season Grass vs. Cool Season Grass

Different grasses thrive in different climates, and planting times differ across species. In general, grasses can be categorized into two separate groups: warm season and cool season. 

Most grass seeds take about a month to germinate, give or take a week. 

As a rule of thumb, it’s best for grass to be planted sometime in spring, but the specifics of each type are outlined for you below.

Weather conditions play a huge role, and you may have to use common sense when deciding the best time to plant. Hopefully, the following advice takes out some of the guesswork.

Warm Season Grass Planting Time

Warm-season grasses are ideally planted within the timeframe of late spring to early summer. Temperatures should be 80 degrees fahrenheit above ground, and about 70 degrees in your soil. 

The reason you should plant from late spring onwards is because you want to avoid any sudden cold snaps once your seeds have germinated. 

Even the hottest mid-spring temperatures can give way to biting winds or unanticipated cold fronts, especially as the weather becomes more volatile worldwide.

All grass seed needs moisture and heat to germinate, but there is a risk post-germination of unexpected cold snaps freezing the water in grass roots. This causes their cells to rupture and kills the blade of grass, or severely hinders its growth.

With that said, cold fronts are not the only thing you need to worry about when planting warm-season grass. 

Sudden droughts or even bouts of dryer-than-expected weather can hurt grass seedlings before they’ve matured, again hindering their growth or killing them outright.

So, how do you ensure that your warm-season grass seed survives the planting? 

A lot of it comes down to chance—at least with regard to the weather. However, here are things you can control: 

• General planting time: Opt for late spring, at the earliest. Use your judgment– for instance, if you’re having an unprecedentedly wet spring, wait for early summertime before sowing
• Keep the soil moist: This applies when the weather is dryer than you expected and the seeds are still germinating. Keeping your soil moist will prevent the seedlings from shriveling up, even during hot weather
• Maintain warm soil temperatures: Windbreakers, pieces of fleece, or other insulators will do the trick just fine if a cold snap hits before your grass seed is established. 

Use it to cover the area and make a shelter for your seedlings without really touching them– they’ll appreciate it and grow more quickly.

Cool Season Grass Planting Time

Cool-season grasses are typically sown early in autumn. The recommended daytime temperature range is between 60 and 75 degrees, with optimum soil temperatures between 50 and 60 degrees. 

If you’re in late summer and it’s already begun to cool down, you may be able to start planting your grass then and there. Just make sure that the soil is moist enough to facilitate germination.

Stick a finger or two into the dirt; if you feel moisture and the temperatures are low enough, plant away. 

If the soil is still dry enough to crumble in your hand, you’d be best to wait until the lower fall temperatures and rain have arrived before sowing.

Similar to warm-season grasses, some things can be done when sowing your cool-season grass seed to ensure that it has the highest chance of successful germination and maturation— regardless of weather and other external factors:

• Use discretion when determining planting time: Although early autumn is recommended, take the time to analyze the weather conditions around you and get to know your soil (more on this later). 

If it is still too hot and dry to sow, wait a week or two and check again.

• Maintain soil moisture: Make sure your seeds or seedlings have enough water all of the time—especially when planting in the late summer period. 

Do not water in the heat of the day, either. Instead, do so in the morning or late afternoon to evening, so that your grass is not burned by evaporating water.

Whether cool season or warm, grass seed needs to be nurtured and tended to with care just like any other living organism. 

With diligence and a bit of luck weather-wise, your grass seed should be up and due for a mow somewhere around the 6-8 week mark.

Preparing The Soil

Soil needs to be tilled so that it’s aerated in time for planting. This is the simple part of preparing the soil, but also the most physical. 

It’s vital to break up the top 3-5 inches of your soil using a hoe, pick, tiller, or whatever other tool you prefer so that no hard crust remains. 

Properly aerated soil means that it has plenty of air pockets within so your grass roots can breathe. 

Highly compact soil doesn’t facilitate fast, effective growth, as roots will struggle to suck up water and may suffocate. 

If your soil’s nutrient content is low, there are other steps you’ll need to take first to prepare it for planting. You can do this by testing the soil.

Testing The Soil

There are many methods you can use to determine the pH of your soil. 

Whether DIY or using a store-bought kit, you’ll be able to determine whether your soil is more alkaline or acidic. From there, you can decide what fertilizer to use to best grow your grass of choice while avoiding any nutrient deficiencies.

The first method of testing your soil is to buy a test kit. These can commonly be found at department or home & garden stores. 

They’re quite simple to use as each kit will come with instructions, but here is the basic process: Put a clean soil sample (i.e., one free of litter or plant debris) into a receptacle, wait a specified amount of time, and the kit will then indicate the pH of your soil.

A less precise but far simpler method is the DIY home test. There are two procedures: One that tests for acidity, and the other for alkaline.

• Acidity: Take your shovel and make a small fissure in the soil between 6 and 8 inches deep. 

Take a few tablespoons of soil and dampen it in a bowl with distilled water. Measure out a half cup of baking soda and place it in the bowl. If the mixture begins to fizz, your soil is acidic.

• Alkaline: Get the same amount of soil from the same depth, and put it in a bowl. Pour a half cup of vinegar onto the soil. If this results in fizzing, your soil is alkaline.

What fertilizer/s you use will depend on your chosen grass and the results of your soil test.

Choosing The Best Grass Seeds 

Based on what you’ve read about climate and grass types, you know now what to do to choose the best grass seeds. 

If your area is warm, opt for warm-season grasses and plant them in late spring or early summer. If you live somewhere cold, plant cool-season grasses mid-autumn.

The best way to make sure you’re getting the grass seed you want is to read the label on the packet.

Reading Grass Seed Labels

Reading grass seed labels is essential. Also known as seed tags, these labels will give you so much information about your grass seed. 

Use the following information in conjunction with this article to determine the specifics of your chosen seed.

What’s On A Seed Tag?

Here are the details you’ll typically find on seed tags: 

• Type and variety of seed: The species and/or subspecies of grass
• Other seeds present: In some packets, 5% or less of the seed content will be some kind of other crop
• Other materials present: Also referred to as inert matter, this will indicate whether there are any fertilizer or mulch products present
• Weed seed and noxious weed: A percentage of weed seed may be present in your grass. This varies by state, and there could be 2+ labels dealing with each kind of weed
• Seed purity/pure seed: If multiple varieties of grass seed are present, they will be listed by percentage value under this heading
• Germination rate: The percentage of seeds that are likely to germinate in ideal condition
• Test and sell dates: An indication of the lifetime of the seeds in the packet, and when they were germination tested
  

Planting The Seeds

You’ve tested the soil, and selected the optimal grass type/s for your area, climate, and soil type. 

Now, onto the fun part. 

Planting the seeds is one of the most rewarding plants of lawn care, and a moment you’ll look back on fondly when your lawn is healthy and mature.

The first thing you want to do is even out the level of your soil with a rake. If it has a lot of uneven patches, consider bringing in more soil to top it up. 

Leveling your soil out properly should also aerate it, but feel free to break up the surface topsoil as much as you want.

Rake the soil into small furrows. Once that’s done, it’s now ready for planting. 

Take small handfuls from your bag of grass seed and scatter them evenly across your lawn, densely. You don’t want them to pile up, but you also don’t want to leave too much dirt uncovered. 

Once your seed is scattered upon the ground, cross-rake the entire area. In other words, rake in the opposite direction to your initial raking. This gives the seeds the highest chance of establishing. 

After this, we go to the next step: watering and mowing the lawn.

Watering & Mowing The Lawn

Be sure to water the entire area of your lawn evenly, without missing a spot. 

When you water, do not hit the seeds directly with a heavy stream, but rather use a fan or spray function on your hose nozzle. 

If you don’t have a hose head, try kinking the hose so the water flow isn’t strong enough to dislodge the seed.

Resist the urge to mow your lawn as soon as you see seedlings pop up. 

Seedlings will emerge far before their roots have taken hold, as they germinate after 7 to 30 days. 

It’s recommended that you wait a minimum of 6 to 8 weeks before giving your new lawn its first mow. It’s worth the wait.

A lawn is established enough to mow after 6-8 weeks, but it can take up to 1-2 years to be considered mature. Mow it regularly, fertilize it if you need to, and watch your lawn take hold.

FAQ

Do You Put Grass Seed on Top or Under Topsoil?

For best results, sprinkle your grass seed over freshly raked topsoil, and then cross-rake the seeded area. 

You can sprinkle some dirt over your freshly planted seeds, but don’t add topsoil.

Will Grass Seed Grow if I Just Throw it Down?

Yes, grass seed will grow if you just throw it down. 

However, you won’t get the best results for your lawn, and it won’t have a high germination rate. You should follow the steps outlined in this guide for the best results.

How Often Do I Water New Grass Seed?

You’ll want to water your new grass seed every day. See above for the best way to water your new grass seed without dislodging them from the soil.