How to Keep Grass Seed on a Slope from Washing Away

Planting new grass seed is tricky because you have to use the right amount during the correct season with near-perfect conditions. Adding a slope into the equation and you can see why it’s difficult to grow grass seed on a slope while preventing it from washing downhill.

To keep grass seed on a slope from washing away:

1. Aerate the soil to plant the seeds
2. Place an erosion control blanket to prevent mudslides
3. Use retaining walls
4. Put straw over the soil
5. Don’t seed the soil when it’s raining
6. Overseed the grass if it’s sparse
7. Roll the soil with a lawn roller

Throughout this article, we’ll break down the step-by-step solution to keep grass seed from washing down a slope, what tools you’ll need to get the job done, and how to make it as easy as possible. Enjoy!

Aerate the Soil Before Spreading the Seeds

Aerating the soil will provide holes for the new grass seeds to sit. Rather than falling downhill, they’ll sink into the dirt and sprout. It’s an excellent way for those who want to prevent the seeds from rolling around, especially if you live in a windy region.

Lawn aerators get rid of moles, too. Moles and other burrowing pests can ruin your sloped lawn, making it very difficult for the grass seeds to grow without washing away. Furthermore, they can cause patches and destroy straw blankets intended to aid the grass seeds.

Your goal should be to provide the best possible growing environment for the grass seed. If it’s on a sloped hill, it’s already fighting an uphill battle (no pun intended). Use a lawn aerator to loosen the soil and add oxygen to the seeds. These holes also help with watering and fertilizing.

Use Erosion Control Blankets for the Grass Seed

Erosion control blankets are crucial for those living in areas that are prone to mudslides. One rainy day is often enough to ruin a whole patch of new grass seed. As the soil loosens and turns to mud, the seeds wash away with it. It’s an avoidable situation if you use an erosion blanket, sandbags, or retaining walls.

Granite Seed explains that the soil can lose its nutrients during a mudslide. Even if the seeds stay in place, they won’t have the nutrition they need to grow. Instead, there will be patches of dirt and dry spots that won’t germinate.

The Sandbaggy Jute Netting is good because it’s a 4′ x 225′ roll of jute that prevents mudslides and natural erosion. The dirt will stay where it is, as will the nutrients. Your grass seed can grow quickly and healthy, not to mention that it’ll benefit from the rain rather than get damaged by it.

Turn the Slope into a Terraced Hill

Terraced hills look amazing and serve another function: They prevent the soil and grass seed from washing down a sloped yard. You can make natural terraces or use retaining walls with landscape fabric to bolster their structural integrity.

Making a terraced hill out of a sloped lawn includes layering it into multiple levels. You can plant grass seeds on each level without worrying about it going downhill since it’ll be on a flat surface. This setup also lets you plant flowers, bushes, and other plants on each portion of the terraced hill.

Add a Straw Blanket to Prevent the Grass From Washing Away

Straw blankets provide protection from the elements for the grass seed. However, adding a straw blanket over a sloped hill with new grass seed will help prevent mudslides and rocks from damaging the germinating seeds. It’s also very easy to remove once you’re done using it.

Most straw blankets naturally deteriorate over the course of a couple of months. You can also follow a recommended timeline to remove a straw blanket from the grass seed. It involves mowing the lawn once the grass is tall enough to support itself without a straw blanket.

Keep these things in mind when using a straw blanket to keep grass seed on a slope from washing away:

1. Straw blankets are very different from erosion control blankets because they break down, whereas erosion control blankets take a long time to go away (if ever).
2. A straw blanket will support the grass seed’s growth for up to two months, but it needs to be removed to help oxygenate the soil.
3. You can’t layer straw blankets or they’ll be too dense for the grass seeds to sprout.

Seed the Sloped Grass Seeds During the Spring

Woodsman Tree Service claims it’s best to seed a sloped yard during the spring or earlier in the summer months to keep the rain away. The rain can wash the seeds away, wasting your time and ruining the grass. On the other hand, if it’s too hot, the soil can dry out and crack.

Water the soil once you seed it, but don’t forget to aerate the soil beforehand. You can also till the soil if it’s too dry or doesn’t have enough nutrients. Top it off with fertilizer and let nature do its work. We’ll show you another quick trick to keep the seeds in place in a short while.

Overseed the Soil if It Rains

It’s always better to rake the dry grass, then overseed the soil once the rain goes away. Overseeding the soil will allow most of it to fall into the soil while some of it inevitably washes downhill. Overseeding is a popular choice for people who grow lawns on hills because it’s so effective.

If you want to add additional seeds, make sure you don’t overwhelm the grass. There should be more grass seeds than usual, but not enough to coat the ground without seeing any dirt. Too many seeds will prevent the germinating grass from growing and getting enough nutrients, oxygen, and sunlight.

Use a Lawn Roller to Push the Grass Seeds into the Soil

Lawn rollers force the seeds deeper into the soil while closing the holes caused by aeration. It’s a great method for sloped hills because the upper layer of dirt can wash away without taking the grass seeds with it. Using a lawn roller also compacts the soil and lowers the chances of mudslides.

If you want to use a lawn roller, you can choose a push or tow behind variant. The GoPlus Lawn Roller is filled with water, letting you choose how much weight you want to put on the sloped soil. You can choose between the 24-inch or 36-inch roller, too.