6 Ways To Keep Grass Seed From Washing Away

If you’ve recently seeded your lawn or have done so in the past, you probably already know how tricky it often is to keep it from washing away after particularly heavy rain. 

This is especially true if your yard is hilly or if the seed you’ve planted lies on a slope! 

Thankfully, this dilemma is more common than you’d think, and there are lots of ingenious methods to keep your grass seed from washing away in the early days after you’ve planted it while it germinates.

how to keep grass seed from washing away

Sprinkle A Thin Layer Of Straw Over Your Grass Seed

Perhaps one of the most effective ways to keep your grass seed rooted in place, so it can germinate properly is to cover it with a thin layer of dry, light straw.

More specifically, after you’ve planted your grass seed and covered it with some soil, grab some handfuls of straw and sprinkle it on top of the entire area. 

The straw will keep the seeds securely in place, even if it rains heavily or is very windy in the coming days.

Another great benefit of this method is it prevents the soil underneath from eroding. 

This also often affects grass seed germination and is another messy, inconvenient issue to deal with when planting anything in your yard.

As a general rule of thumb, the straw layer should be thick and heavy enough to coat the area thoroughly yet still thin and light enough to see the dirt underneath. 

Avoid saturating the area with too much straw, as this will also weigh down your seeds and keep them from sprouting properly.

This option works well even for steep slopes and inclines where you’ve planted new grass seed, even in the case of high winds and heavy rain!

Use Specialized Netting To Prevent Soil And Seed Erosion

If your grass seed keeps washing away or you’ve planted it on a slope, erosion control netting is an excellent, simple, and inexpensive way to keep it in place for a few days, so it can eventually sprout as normal.

Ideally, you want to use netting with somewhat wide openings to ensure the seed can sprout properly. 

Keep in mind not all types of erosion control netting are designed for grass seed. 

If the netting is woven very tightly together, it will interfere with and inhibit the grass seed’s ability to germinate and grow. 

Biodegradable netting is best, as it will eventually break down naturally with no extra help from you, and you won’t have to go back and remove it later.

For example, EarthAid Slope Saver PRO Erosion Control Kit is a type of natural netting made from jute, and it works especially well for keeping newly-planted grass seed from washing away. 

As the product suggests, it’s ideal for anything planted on slopes that would normally be very prone to eroding in the rain and wind, but it’ll work well even for grass seed planted on flat ground, too.

There are also erosion control blankets, which work mostly in the same way as netting. 

This A.M. Leonard Curlex Erosion Control Blanket protects the seed from washing away and provides it with nutrients as it breaks down into the soil. 

It’s also biodegradable, so eventually, it’ll disappear without a trace once it’s finished its job. 

Its barbed fibers are designed to cling to the soil without eroding itself, and it retains moisture very well.

Use The Right Kind Of Deep-Rooting Grass Seed

Interestingly, the grass type you use will also affect how susceptible it is to wash away in heavy rains. 

You should look for grass seeds that naturally establish deep roots, like very tall fescue grasses or buffalo grass.

One type of seed we recommend for areas prone to erosion, such as steep slopes, is Scotts’ Turf Builder Tall Fescue Mix

Learn how long it takes Scotts Weed And Feed to work in our detailed article here.

This particular type of grass seed not only has naturally deep roots, but it also is very durable and resistant to conditions that would normally damage it, such as: 

  • Droughts 
  • Heat
  • Turf diseases
  • Various insect pests

This product is also available in several different sizes, so you’ll be able to select exactly the amount you need for the area of your lawn you’re reseeding.

Fescue grasses like Scotts’ Fescue Mix mentioned above also grow quickly and produce very durable coarse grass, so it won’t be nearly as prone to washing away as less dense types, regardless of where you plant it. 

Using quality seeds is one of the easiest ways to keep them from eroding before it germinates. 

Another great option is Jonathan Green’s Black Beauty Ultra Grass Seed

This seed is a mixture of a few different dense types of grass, including tall fescue, Kentucky Bluegrass, and perennial ryegrass. 

This one is also highly resistant to insects and other damage, and its roots can grow up to 4” inches deep to ensure it won’t be washed away, even if it’s on a steep incline.

Apply An Starter Fertilizer After Planting Your Grass Seed

To prevent your seed from washing away, you should focus on getting it to root as quickly as possible. 

This process will take a few days, no matter what you do, but you are able to speed up the process a bit with the right kind of fertilizer. 

More specifically, you should apply a starter fertilizer to your grass seed immediately after you plant it.

We’ve got to go with Scotts again for our recommendation here, as their Turf Builder Starter Food For New Grass is a great option, especially when paired with their Turf Builder tall fescue seed mix we mentioned earlier.

It works well to ensure the seed establishes deep, sturdy roots from the start and gets the nutrients it needs to grow as quickly as possible. 

What’s more, it’s conveniently available in different sizes, which clearly state exactly how many square feet each package covers.

Using the right fertilizer for your grass seed will not only ensure fast, healthy grass growth but will also help it germinate and sprout faster than usual. 

This is great for preventing erosion, especially if you realize you’ve got a storm coming in the next few days after you’ve already planted the seed. 

Fertilizer also ensures your grass maintains a more vibrant, healthy-looking green color as it grows.

Water The Seeded Area Often

This one seems like a bit of a no-brainer at first, but knowing how often to water your grass seed right after you’ve planted goes a long way in getting it to germinate and sprout quickly and effectively. 

Comprehensive, proper lawn care from start to finish includes proper watering!

In general, you’ll need to make an effort to water the grass seed twice a day: once very early in the morning around 8:00 AM or so and again sometime in the early afternoon, or around 2:00 or 3:00 PM. 

Importantly, you want to also be sure you don’t overwater your seed, as this will only make it more prone to washing away.

Ideally, the top 2” inches or so of the soil where you’ve planted the seed should be moist after watering but not drenched and muddy. 

Use small, gradual amounts of water until you’re sure the grass seed is saturated, and go slowly to avoid overwatering it.

Crucially, avoid watering the seed too late in the day. 

If you water it on a particularly hot afternoon while the sun is directly overhead, you’ll risk the water immediately evaporating and leaving the soil even drier than before. 

Alternatively, if you water it very late in the evening once the sun sets, the water will sit on the soil and leave it prone to fungal growth and turf diseases. 

This is why watering early in the morning and again in the early afternoon is best to both keep your lawn moist enough for the seeds to germinate and also keep them from eroding.

For more details, check out our guide for how often to water grass seed and for how long.

Aerate Your Soil Before Planting Your Grass Seed

Heavily compacted soil will prevent your grass seed from germinating, as the seeds won’t be able to break through its hard, dense surface. 

This is why aerating your soil beforehand goes a long way in preventing grass seed from washing away, as it can germinate a lot faster in aerated, loose soil. 

Even if only a small layer of soil is compacted, a compacted layer as little as 1/4” inches will potentially prevent the grass seed from sprouting.

There are a few ways to aerate your soil, from a core aerator to a manual aerator. 

Dethatching is also a good idea, as this will make the lawn aeration more effective and further encourage air to flow deeper into the soil.

In the end, by both aerating and dethatching before planting your grass seed, you’ll get much thicker, healthier, and stronger grass, and it’ll grow a lot more quickly than if the soil was at all compacted beforehand.

Check out our guide to aerating your lawn by hand like a pro.