Certification of Blends and Mixtures


Occasionally, it may be desirable, whether from a seed marketing perspective or customer demand, to provide the buyer with a blend or mixture of certified seed comprised of two or more varieties. AOSCA rules permit blending certified seed to create a certified blend but there are specific requirements to ensure the quality and identity of that product.

Blends vs. Mixtures

A blend is a controlled mixture of two or more varieties of the same kind, each of which exceeds 5% of the total by weight. An example would be two different wheat varieties blended together in the same container. A certified blend requires that EACH component of the blend is certified. These components are certified as pure varieties and blended after they have passed final certification.

A mixture means seed consisting of more than one kind, each in excess of 5% of the total by weight. An example would be a pea/oat mixture or a cover crop mixture. Often, certified varieties are used in mixes with non-certified (or common) varieties. This is permissible by law, but if a mixture involves a PVP Title V variety, that variety must be certified before it is added to the mixture.  

According to the USDA AMS, Seed Regulatory and Testing Division, seed lots comprised of mixtures of kinds or blends of varieties can be provided with mixture or blend names. However, labeling and advertising of mixtures and blends must not create the impression that the seed comprising the mixture or blend is a single variety. Also, a variety name cannot be used as a name of a mixture or blend, even if the variety is a component of the mixture or blend.

Basic Requirements

Registration of the Blends

Blends/mixtures must first be approved by the North Dakota State Seed Department to be accepted under this program. In order for blends to be labeled as certified the following information is required: 

  • name the blend as it will be marketed
  • name and percentage of each component
  • each component of a certified blend must be certified
  • permission from variety owners of each component in the blends

Applicants must complete the form Registration of Blends or Mixtures of Seed and submit to the department for approval. If the blend includes a protected variety, permission must be obtained from the variety owner for use in a blend. Documented evidence must be provided with the registration form.

The formulation of the blend shall not vary by lot or year. The certified seed conditioner must also demonstrate the ability to blend the component varieties within specified tolerances.

Only Certified class seed of each of the component varieties may be used in a certified blend. Proof of certification must be provided to the department prior to blending. Proof may be a certified seed tag or bulk certificate.


The certification label must specifically state “Blend” or “Mixture” and meet all other labeling requirements. The labeler has the option of stating the variety name of the components and proportions on the label.