C. Selecting and Estimating Seeding Materials

In this section we are going to take a look at seeding materials. The list will be short, but each item is very important for a successful lawn. Seed, soil, fertilizer, and soil amendments are the basic key elements we will talk about.

Soil is usually sold by the cubic yard. Fertilizer and seed are sold by the bag.

Once you know the dimensions of your yard, you can easily estimate how much fertilizer and seed you will need.

Topsoil may be a little more challenging to estimate, but we will provide you with a formula to get you pretty close.

For grass seed to establish into a beautiful lawn, you will need a good base of soil to start from. Seeding Materials will walk you through the importance of using quality materials. Then we will show you how to estimate how much you will need.

The grass seed has to be a variety that does well in your specific climate. There are warm season, cool season, and transition zone grasses, with some varieties able to thrive in more than one climate.

Fertilizers used for seeding grass are referred to as "starter" fertilizers. They have special blends designed for the root system that are high in phosphorus. This gives a great boost to your new lawn by encouraging accelerated root growth.

Amendments are important to improving soil conditions in two ways. You can amend soil with additives like lime to change the pH level of your soil. The other way amendments help is by changing the physical structure or quality. Adding humic acids, or organic topdressing can improve both sandy, and clay soils.

For those of you renovating an existing lawn, please visit our module on lawn repair. Here you will find a more in depth look at diagnosing and repairing existing problems.

Let's start off with what goes into building a good base.

The importance of good soil

Before we get into estimating what you need for seeding grass successfully, we first want to discuss the soil depth, and quality. It's been said in landscaping many different times and ways, "Don't put a $20 dollar plant in a $2 dollar hole."

The same thing goes for grass, don't cheap out on soil. Unless you want to do this again in a few years, do it right the first time. Spreading an inch or two of loam over a heavy clay base is not going to bring you long term success when lawn seeding.

The ideal soil is loam. Loam is a healthy mixture of organic matter, sand, silt, and clay. Loam has the ability to take moisture rather easily, and retain it.

To have a successful lawn for the long term, you need to have good soil composition combined with proper pH balance. A nice rich loam is the perfect composition, and a PH balance of 6 or 7 is ideal for most lawns.

Combined with proper lawn care, this soil will allow you to have a nice thick, lush, green lawn with deep roots. Your lawn will combat weeds, drought, heat, cold, pests, and diseases much better. It will also require less chemical treatments and fertilizers saving money and the environment.

A nice rich loam contains billions of microscopic organisms called microbes. Microbes turn the building blocks into soluble foods for the root system. For those of you that practice organic fertilizing, these microbes are vital in breaking down the organic fertilizers.

Testing Soil

Generally, the east cost of North America has a more acidic soil from the rains. The dryer regions of the west tend to have a more alkaline soil. This is not always the case, and you should have your soil tested if you are unsure of your conditions.

If you can, try to test at several different locations in your yard. (The conditions can vary from point to point.) You can purchase soil test kits from most garden centers to measure the pH level of your soil. pH is a number scale to measure if you soil is acidic (below 7), neutral (7), or alkaline (above 7).

Most grasses do well with a pH level of around 6 or 7, but it's up to you to know what your seed requires. The lower the pH number the more acidic your soil will be.

If your soil is very acidic, you can raise the pH level by applying lime. This will help neutralize the acidity. If you don't do this, the effectiveness of the fertilizer will be greatly reduced. Your lawn will not respond as well to the fertilizer, with growth and color changes.

It's important not to raise the pH level too fast, or by too much at one time. This can have damaging effects on your lawn. If the soil is very alkaline, than you may have to use sulfur, or an iron sulfide enriched fertilizer to lower the PH level.

If you want to know if there is a lot of clay in your soil, take a handful of dirt and squeeze it into your hand.

Clay will stay together in a tight ball when you roll it around.

Clay soil is very poor for draining water, and contains very little oxygen. If you have a lot of clay in your yard you should excavate enough of it now, to allow for about six to eight inches of loam.

This is the easiest, fastest, and most effective way to deal with it.

Humic acid, and organic topdressing can break down and amend clay soil, but in smaller amounts over longer periods of time.


You can make your own loam by using the dirt you already have and tilling in amendments. This is an option for people with a low budget, or areas where loam is very expensive.

There are many different amendments you can use. Check with your garden center, or landscape supply store to see what the have available. Many garden centers make their own blends, and give them their own trade names.

I have grown some beautiful, lush, thick, and green lawns creating my own loam at a fraction of the cost of trucking in large amounts.

Tilling can be very hard work so be prepared for it. If your soil is parched, dry, and hard, soak the area one or two days before you till. Don't till when it is wet or soaked, let it partially dry out for a day or so. This makes tilling a little easier.

Till down six to eight inches if you can, and break up the hard packed dirt underneath. This will allow you to remove large rocks that may impede root growth. Tilling will loosen up the soil so the grass roots can penetrate deeper into the ground. It will also allow oxygen and water to penetrate the root system more effectively.

Add in your amendments and till the area again thoroughly so you have a consistent quality soil. If your soil is very heavy with clay, you can add sand and organics to break up the consistency of the clay and improve drainage as well.

Try to use more organics than sand, as they are more effective. Don't till clay if it is very wet. This will hurt you more than help you.

Again, your goal is to have a nice rich loam. If squeezed in your hand it will form a ball, but will crumble apart when your roll it around.

Hopefully, now you have a better understanding of soil, and the importance of having the proper depth of good soil? You may spend a few hundred dollars more up front for an extra load or two of loam, but you will save that in the long term having a much healthier and environmentally friendly lawn.

Estimating Loam

The first things you need to know about loam is that it is prone to compaction. You will need to increase your order roughly 30% more than the formula tells you to account for this.

If you laid down 6 inches of loam, it would quickly compact to approximately a 4 inch layer. I have seen countless landscapers make this basic mistake over and over again. Other people just try to cut corners to save money, but pay for it later on down the road with a poor lawn.

To estimate the amount of loam requires you to know the dimensions of your area. Loam is usually sold by the yard. To convert cubic feet to yards, divide the cubic feet by 27.

For example:

An area that is 40 ft. long by 40 ft. wide and has a requirement of 6 inches of loam will look like this.

40 ft. times 40 ft.= 1600 sq. ft.

Times a depth of 6 inches (.5 of a foot)= 800 cubic ft.

Divide this by 27 (conversion factor from cubic ft. to yards) = 29.62 yards of loam.

This 29.62 is the amount that should be increased to accommodate for compaction. Make it compatible with the amount of loam your trucks are bringing each trip to be efficient. 3 truck loads of 12 or 13 yards would be the right order.

A little more won't hurt you, but not enough will.

If you are curious on how we got the .5 of a foot just take the inches and divide by 12. (12 inches in a foot.)

The trucks are usually a single axle or tandem axle, it could be a 10, 12, 14, or even 16 yard load. Some areas also have truck and pup, or truck and quad wagon combinations that can bring double loads.

Ordering Seed

For ordering seed, you need to know the square footage of the area. Your local farm supply store will be able to tell you how much you will need from that. They can supply you with bulk bags if you have a large area.

If you only have a small yard (less than 1,000 sq. ft.), you can probably find a good selection of grass seed from any store with a garden center, or seasonal section. Follow coverage instructions on the bag.

There are probably a few dozen different varieties of grass in the world depending on where you live, but the suppliers and stores have already done the ground work for you. They very rarely will sell varieties that aren't suited for your area.

Make sure you don't cheap out on seed though. Get a good quality recognized brand name that you are familiar with. In case you need some help with seed comparisons, and what are best suited for your yard and conditions, you can visit this handy link for assistance. How to choose grass seed.

Stay Away From lower quality seeding materials...

Bags that do not specify what type of seed you are buying. (They will say VNS, meaning variety not specified.)

Old seed. Try to have fresh seed that is dated for the current year.

Annual grasses mixed in the bag.

Bargain seeds that may contain high amounts of noxious weed seeds.

READ THE BAG. It only takes a few minutes, and will tell you the coverage, the seed types, and the usage of the seed (shade, sun, and if it withstands heavy foot traffic or not).

The last thing you will require for seeding materials will be a good starter fertilizer that is high in phosphorous. This will encourage root growth for you newly sewn seed. The coverage amounts should be included on the bag itself. (If not put down a couple of pounds for every thousand square feet or so.)

Now you have a better understanding of Seeding Materials, and how to estimate your requirements, we can move on to the next section.

Onto Grading Soil for Seeding.


Table of Contents: Seeding a Lawn

Introduction: Seeding a Lawn

A. Seeding Site

B. Seeding Tools

C. Selecting and Estimating Seeding Materials

D. Grading Soil for Seeding

E. Spreading Seed

F. Seeding Completion and Clean-up


Go to The Yard: How-to Modules

Return to the Dream Yard Home Page from Seeding Materials


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