How to Plant Grass Seed on Hard Dirt and Get It to Grow

Published on 02/22/23

Planting Grass Seed on hard dirt — Faba Photography / Getty Images

In This Article

Hard Ground Causes
Before Getting Started
Preparing Hard Soil for Grass Seed
FAQS

Project Overview

Working Time: 2 - 4 hrs
Total Time: 3 days - 4 wks, 2 days
Yield: 10,000 sq. ft.

Skill Level: Beginner
Estimated Cost: $400-1500

Hard, compact dirt can be a problem when it comes to sowing grass seed successfully. Grass seed is surface sown, meaning lays and roots on top of the soil, so it does not need to be buried. It's usually broadcast over the ground with a hand or rotary spreader. In order for that seed to sprout, it needs good soil contact, which makes soil quality a major factor in growing a healthy, uniform lawn.

Hard ground can cause issues when it comes to grass seeds. Since the seeds will have difficulty penetrating the soil, it could prevent grass seeds from rooting. If you're trying to plant grass seed on hard dirt, the first step is to identify the problem and repair the planting area.

Here's what you need to know about trying to plant grass seed on hard dirt.

What Causes Hard Ground?

Hard ground is caused by new construction, high traffic, and environmental factors like flooding, drought, and wind. Gardeners and landscapers would call this layer of ground topsoil, which is what turf grasses grow in.

Surface layer crusting: High winds and dry conditions can cause the surface layer of soil to be hard and cracked. The shallow crust lacks the moisture needed for turf grass seeds to germinate. It's should be broken up before planting, which is usually easy to accomplish with a hoe or rake.
Too much thatch: Thatch forms when organic debris accumulates more rapidly than soil organisms can break it down. A thick layer inhibits root growth, air circulation, and nutrient uptake. Thatch builds up on existing lawns, so if you plan to make repairs by overseeding, you may need to dethatch before planting.
Clay soil: Clay is a component of almost all topsoil, but too much could mean problems for soil composition. Clay soil is dense, retains water, and lacks the nutrients and air circulation needed to support plant growth and health. If your topsoil has too much clay, steps should be taken to amend it before planting grass seed.

Before Getting Started

Obtaining a soil analysis can save you effort and cost. Lawn grasses grow best with a balanced pH of 6.0 to 7.0 and hard, clay soils indicate a pH level higher in alkalinity. Soil testing will tell you when you need to lower pH.

Equipment / Tools

Rototiller or shovel
Hoe, hard rake, garden fork
Broadcast spreader
Hose and sprinkler

Materials

Soil conditioner or compost
Elemental sulfur if needed
Starter fertilizer
Water
Turf grass seed
Straw
Gloves
Eye protection

How to Prepare Clay Soil for Grass Seed

Remove Weeds, Rocks and Debris

Clear any obstructions from your planting area. Working the soil will go more smoothly and removing rocks and sticks prevents the potential hazard of flying debris.

Remove weeds by hand, if possible. Commercial weed killers require a waiting period of 1 to 4 months after application before planting grass seed.
Test for Moisture

Breaking up hard ground that is too dry or too wet can cause further damage. Test for moisture by digging down 6 inches. Mold a handful into a ball. When squeezed, it should crumble easily. Soil too dry won't mold; too wet won't crumble.

Water an overly dry area thoroughly and allow it to absorb for 2 to 3 days. If too wet, allow it to dry out for several days and retest.

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Add Elemental Sulfur if Recommended

If your soil pH is greater than 7.0, apply the recommended amount of elemental sulfur and use the hard rake or rototiller to work it in. Allow a month for good absorption.
Add Compost or Starter Fertilizer

Starter fertilizers and compost also lower soil pH but work more slowly. Compost is not practical for existing lawns, but both amendments can be added just before seeding a new lawn. Starter fertilizer can also be applied right after planting but should be broadcast and watered in.
Break Up the Soil

A depth of 3 to 6 inches is adequate for growing grass. A rear tine rototiller works best on clay soils and allows you to add amendments at the same time you prepare the seed bed. Plan to make several passes to achieve a good mix of soil and fertilizer or compost.

If using a shovel or garden fork, turn over all the soil to a depth of 3 to 6 inches. Then use a hoe to break up large clods. Spread or broadcast soil amendments and use the rake and hoe to work them into the soil.

Whichever method you choose, smooth and level the planting area with a hard rake.
Sow Turfgrass Seed

Use a broadcast spreader to apply seed. Divide the recommended amount of seed in two. Use one half to cover the area in a horizontal direction. Use the other half to seed across in a vertical direction. The seed can be lightly raked for even spread.
Water in the Seed

A hose with a spray nozzle or sprinkler should be used to water thoroughly to a depth of 3 to 4 inches. Avoid using a strong, direct spray which can disturb the planting bed and wash away seed.

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Cover Lightly With Straw

A light covering keeps seed in place until it roots in. At least 50 percent should receive sun exposure so keep the mulch application fairly thin.

FAQ

Can you sow grass seed on hard ground?

Grass seed is expensive and failure to work up the soil will result in a spotty lawn, at best. Determining the underlying cause of compaction and fixing the problem first, saves you time, effort and cost.
How can I soften hard ground?

Hard topsoil soil is often too alkaline which inhibits plant growth. Compost, nitrogen fertilizers and elemental sulfur all lower alkalinity which loosens the soil, increases air circulation and improves nutrient uptake.
Is there better grass seed for hard ground?

Tall fescue is the recommended cool-season variety for clay soil, with Bermuda grass the better choice for a warm-season grass seed.