What Are Certified Seeds? (How They Protect Growers)

If you are wondering what certified seeds are, then you are not alone.  I was curious about what certified seeds are, how seeds become certified, and what seed certification means.

So, what are certified seeds?  Certified seeds are produced and labeled following rules and standards of a government seed-certifying agency.  Certified seeds ensure that growers and buyers get the crop and variety they want, with a high germination rate and minimal contamination by the seeds of weeds and other plants.

Of course, different countries will have different standards for certified seeds.  In fact, different states within the U.S. all have their own standards for certified seeds.  Let’s take a closer look at certified seeds, including how they are certified and what seed certification means.

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What Are Certified Seeds?

According to the NC State Extension, certified seed is “seed that has been produced and labeled in accordance with the procedures and in compliance with the requirements of an official seed-certifying agency.”

This means:

  • there are strict requirements for producing certified seeds
  • the seeds must be properly labeled with various information (more on this later)
  • a seed-certifying agency must certify the seeds

The AOSCA (Association of Official Seed Certifying Agencies) serves the third purpose (more on this later).

Certified seeds need to have a tag indicating their germination rate (among other things). The germination rate tells you what percentage of planted seeds you can expect to sprout.

Seed certification started in 1919 in the U.S. and other countries.  The purpose was to respond to farmers who complained about seeds that were low-quality or had been misrepresented to them by vendors.

In 1929, the Federal Seed Act established rules to regulate the trade of seeds.  The Act also defined a process for certifying seed.

For more information, check out this article on certified seeds from the NC State Extension.

Now let’s take a closer look at the standards for certified seeds.

Certified Seed Standards

According to the USDA, state seed certifying agencies give official recognition to seeds of a particular variety, “which ensures genetic purity, identity, and a given minimum level of quality.”

This includes testing for the genetic purity of parent plants, along with tight controls on how the seeds are produced.  These tight controls prevent the seeds of weeds or inferior plants from being mixed in with certified seeds.

Strict controls limit the amount of seeds from grass or other weeds and undesirable plants that show up in lots of certified seeds.

Every lot of seeds (both certified and non-certified) also have a seed analysis tag.  The seed analysis tag includes the following basic information:

  • Kind and variety – species or common name, along with cultivar or variety name of the plant.  This information helps to distinguish the seeds from others of the same kind.
  • Lot number – a defined quantity of seeds, within an allowed “error” or tolerance.  This is similar to what you get from seed catalogs: a packet of 1000 seeds, 1 million seeds, etc.  Nobody is really counting out 1 million seeds.  Instead, they use a method such as average weight of a seed to give you an amount that is “close enough” to 1 million.
  • Origin – the location where the seed was grown.  At a minimum, identifies a state in the U.S., and possibly more detail.
  • Net weight – total weight of container
  • Pure seed – Purity, expressed as a percentage.  For example, if the seed is 97% pure, then it contains 97% of the listed seed and 3% of either inert matter, seeds of weeds, and other crop seed.
  • Germination – Germination rate, expressed as a percentage.  For example, if the germination rate is 95%, then if you planted 1000 seeds, you would expect 95%, or 950 seeds, to sprout.  This assumes favorable conditions for the seeds (i.e. no extreme temperature or humidity levels).
  • Dormant seed – The percentage of seed that did not germinate during a test.
  • Germination test date – The germination test determines the germination rate.  Most states require a germination test date within the past 6 months.
  • Inert matter – this includes dirt, plant parts, and damaged seeds that will not germinate. 
  • Other crop seed – The percentage of seed that comes from a plant not the one listed under “kind and variety”.
  • Weed seeds – The percentage of seeds that are from undesirable, troublesome, or unwanted plants.
  • Name of restricted noxious weed – Expressed as a number per pound of seed, noxious weeds are destructive and difficult to control.  These are allowed in seed lots, but their amount is restricted.  Restrictions vary by state.
  • Name and address – the name of the company that performed the analysis, usually the grower or producer of seed.  It may not be the seller or distributor.

For more information, check out this article on certified seeds from the USDA.

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How Are Certified Seeds Produced?

The AOSCA (Association of Official Seed Certifying Agencies) assists clients “in the production, identification, distribution, and promotion of certified classes of seeds.”

pumpkin seeds
The AOSCA consists of agencies that help with testing and record keeping to comply with seed laws.

The AOSCA can assist with record keeping and procedures to comply with laws at the state, federal, and international levels.

Requirements for producing certified seed include:

  • Special land requirements
  • Planting eligible stock
  • Field inspections
  • Proper seed labeling
  • Meeting standards based on complete lab analysis

For more information, check out the Association of Official Seed Certifying Agencies on the AOSCA website.

Why Use Certified Seed?

There are several good reasons to use certified seed.  For one thing, certified seed ensures that growers and buyers of produce get the crop and variety they want.

Certified Seed Ensures That You Plant The Crop And Variety You Want

Imagine planting a seed that you thought was a Roma tomato, only to find out that the plant ends up bearing cherry tomato fruit.  Although still edible, this is not what you were expecting!

grape tomatoes
Imagine getting tiny grape tomatoes when you thought you were planting Roma tomatoes! Even worse, imagine this happening to a farmer’s entire tomato crop! Certified seeds prevent this from happening due to stringent labeling standards.

Now imagine this happening on a larger scale, such as a farmer’s entire crop of tomato plants.  The farmer would be unable to fulfill his obligations to his buyers, who were expecting Roma tomatoes, and are unable to accept cherry tomatoes.

This is why it is so important to certify seeds, which includes proper labeling.  Pure seed with a high germination rate does not help anyone if they are not labelled properly!

In addition to getting the right type of plant and the correct variety of that plant, certified seeds also ensure a minimal amount of “other” material in a lot of seed.  This other material includes seeds that will not germinate, weed seeds, dirt, and seeds of other plants.

For one thing, this prevents invasive species of weeds from crossing state lines.  If a species of weed takes hold in one grower’s fields, it can quickly spread to other surrounding fields.

You Can Trace The Origins Of Certified Seeds

When you buy certified seeds, you know the kind and variety, along with the origin (for example, produced by a university).  You also know what to expect as far as germination rate, and whom to contact if the seed is not as you expected.

Certified Seed Is Productive

Certified seed has minimum requirements as far as germination rate.  You know that are you getting minimal “other” material in a seed lot, and that a certain minimum percentage of the viable seeds will germinate.

What Are The Four Types Of Seeds?

According to the USDA, the four recognized classes of certified seeds include breeder seed, foundation seed, registered seed, and certified seed.

There is a sort of “hierarchy” among the seed classes, based on which seeds a plant is grown from:

Breeder seed > Foundation seed > Registered seed > Certified seed

For example, a breeder seed can produce a plant that yields foundation seed, registered seed, or certified seed.  However, a registered seed cannot produce a plant that yields breeder seed.

So, what does it mean to be in each class of certified seed?

Breeder Seed

According to the USDA, breeder seed is “controlled by the originating or sponsoring plant breeding institution, firm, or individual which is the source for the production of seed.”

Breeder seeds have a white certification tag.

Foundation Seed

Foundation seed is the offspring (seed) of plants grown from either breeder seed or foundation seed.  The plants and seeds must be handled properly to maintain “specific” genetic purity and identity.

The Department of Agriculture and Forestry determines acceptable production and handling methods for foundation seed.

Foundation seeds have a white certification tag.

Registered Seed

Registered seed is the offspring (seed) of plants grown from either breeder seed or foundation seed.  The plants and seeds must be handled properly to maintain “satisfactory” genetic purity and identity.

Registered seeds have a purple certification tag.

Certified Seed

Certified seed is the offspring (seed) of plants grown from either breeder seed, foundation seed, or registered seed.  The plants and seeds must be handled properly to maintain “satisfactory” genetic purity and identity.

Certified seeds have a blue certification tag.


Now, you have a much better idea of what certified seeds are, and what you are getting with certified seeds.  You also know what to look for to determine if seed is certified.

I hope this article was helpful – if so, please share it with someone who can use the information.

Want to learn more about seeds? Check out my article on savings seeds, and my article on the pros and cons of hybrid seeds.

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Jon M

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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