Will Grass Seed Germinate on Top of Soil?

When you need to refresh or restart your lawn, planting high-quality grass seeds is a great place to start cultivating a green space. 

How do you go about proper grass seed germination to ensure you have a lush lawn? 

Will grass seeds germinate on top of the soil, or do you need to take a layer of soil over the seeds to germinate?

Key Takeaway:

It’s possible to grow grass seed by spreading it on top of the soil. However, uncovered grass seed isn’t typically as effective as placing the seeds under a thin layer of topsoil. Exposed seeds run an additional risk of being moved away from where you planted them or drying out too much.

If you want to ensure your grass plants thrive as much as possible, keep reading! 

We’ll go over everything you need to know for both warm-season grasses and cool-season grasses.  

will grass seed germinate on top of soil

Can You Just Put Grass Seed On Top of Soil? 

While there is the risk of the seeds getting swept or washed away, it is possible to grow grass seeds on top of the soil. 

However, it’s not as simple as pouring the uncovered grass seedlings on your lawn and hoping for the best. 

Before laying your grass seed mixtures on the lawn, you’ll want to prepare the ground just like if you were gardening anything else. 

Weeding the Area

To start, you’ll want to clear the area of weeds. 

If you’ve kept a garden, you know weeds are known for causing unideal conditions for your plants, stealing away nutrients. 

The same is true for a lawn with grass, so get rid of any weeds before getting started!

 Leveling the Lawn

If you’re after a more level lawn, grab some topsoil. 

This is a great way to fill in any noticeable holes or sudden changes in elevation. 

Aerating the Soil

Aerating the topsoil will help increase the chance of germination as well. 

For this, use an aerator or even a digging fork and create small holes in the soil with your tool. 

You don’t need to fully till the soil, though. 

Preparing the Soil

Since the goal is to ensure these grass seeds germinate and grow into mature grass, there are a few extra steps to take to check and prepare the soil for your new grass. 

First, check the pH of your soil. 

You want something balanced here, so pay attention to if the soil’s pH is high or low and adjust it accordingly. 

Adding some starter fertilizer will help promote germination as well. 

Add the Seeds

Once you have your prepared soil, start scattering your grass seed. 

It’s possible to do this by hand, but for larger areas, tools called seeders can help you make short work of the project.

Should You Put Down Topsoil Before Seeding? 

Not necessarily. 

While additional topsoil is handy, the step we discussed earlier to aerate the soil helps prepare the topsoil you already have without introducing more. 

As mentioned before, it’s possible to turn to topsoil if one of your worries is changes in elevation on your lawn. 

The extra layer of topsoil here will help give your lawn a more even surface. 

How Long Does It Take for Grass to Grow from Seed? 

Once you throw down the seeds, your grass lawn won’t crop up overnight. 

There’s a rather large window where you might start seeing results. 

On average, you might start to see results growing as early as a week after you plant them, although it can take up to 30 days to see results. 

In most cases, you’ll have to wait closer to 30 days to see your lawn grow fully enough to mow. 

Until then, you may see grass with soil still visible. 

How Do I Speed Up Grass Germination? 

There are a few things to do to speed up growth. 

We’ve already discussed steps such as soil aeration and fertilizer to boost the nutrients available to your baby grass seedlings.

You’ll also see faster results if you stay off the grass seed. 

Increased foot traffic and unnecessarily heavy traffic or shifting will make germination more difficult. 

Light, frequent watering also helps to keep the soil moist and encourages growth. 

Like almost any other plant, your grass blades need water to both look green and have healthy root growth.

Finally, opt for coated grass seed to help retain moisture properly. 

If you don’t have coated grass seed, it’s possible to find coating applicable to uncoated grass seeds. 

We recommend checking out a seed coating like this one on Amazon.

What Month is Best to Put Grass Seed Down?

Different grass seeds are best planted at different periods throughout the year.

Further Reading: Best time to plant grass seed in Michigan

Cool-Season Grass Seed

If you have cool-season grass, you’ll want to plan to lay your mixture of grass seeds out in the fall. 

The goal is to plant the grass in fall weather but not so close to winter. 

If you plant too late, the grass may not germinate before the harsh temperatures in winter. 

Ideally, you won’t want to plant any later than the end of October. 

This may even be too late in some climates, so pay attention to the climate cycle in your locale. 

Warm-Season Grass Seed

On the other hand, warm-season grasses are best planted in the spring. 

When the soil temperature is consistently about 65 to 70° degrees Fahrenheit (21° C), it’s the ideal condition to lay your grass seed. 

Plus, one of the advantages of spring planting, aside from warm soil, is the rainy weather in late spring. 

This can help with your watering tasks. 

What Happens If You Put Too Much Grass Seed Down?

Worrying about whether enough seeds will germinate is one of the common reasons homeowners might be tempted to put down more grass seed than advised. 

This will hurt your chances, though. 

When you lay out too much grass seed in one spot, you end up with all of the seeds competing with each other. 

Without a ready availability of resources and a need to fight to survive, overseeded lawns are likely to lead to poor germination.