Understanding Seed Labels
As a horse owner, you always have to think ahead in order to stay ahead. Even though we are in the winter months now, Spring is right around the corner which means you should be thinking about Spring pastures and possibly pasture renovations. Here are a few helpful hints to make sure that you are getting the best seed for your money.
There is a “Seed Law”. This law requires seed being sold to adhere to a minimum set of guidelines and standards which should be listed on a suitable label. Access the North Carolina Seed Law. There are certain exemptions and additional standards which can be found in the NC Administrative Code Title 2, Subchapter 48C. Not all bags of seeds are created equal, even if they follow the seed law. There is a large amount of variation in seed quality. Adherence to the seed law only guarantees that the bag of seed you are purchasing meets the claim on the bag so it is important to shop around and compare labels.
So what has to be on the label? What does this information mean? (Information from “A Simplified Guide to Understanding Seed Labels”)
- Variety and Kind – Cultivar/release name, species and common name
- Lot number – A series of letters or numbers assigned by the grower for tracking purposes
- Origin – Where the seed was grown
- Net weight – How much material is in the container
- Percent pure seed (purity) – How much of the material is actually the desired seed
- Percent inert matter – How much of the material in the bag is plant debris or other materials that are not seed
- Percent other crop seeds – Other non-weed seeds
- Percent weed seeds – Seeds considered weed species
- Name of restricted noxious seed (with number per pound of seed). Noxious weed species vary by state. There are 2 types of noxious weeds – restricted and prohibited. Restricted weeds are listed as number of seeds per pound of material in the bag. There should be NO prohibited weeds.
- Percent germination (germ) – An average percentage of seed that will germinate readily
- Hard seed – Seed which does not germinate readily because of a hard seed coat
- Dormant seed – Seed which does not germinate readily because it requires a pre-treatment or weathering in the soil. (Some suppliers may combine hard and dormant seed on the label).
- Germination test date – Date should be within 12 months of the planned date for using the seed
- Name and address of the company responsible for analysis (seller or grower)
The Natural Resources Conservation Service’s Plant Materials Program recommends using seed labels to help you shop around for the best value that will meet your needs. They suggest that you always check the purity/germination and if it is very low, you might not want that variety or mix. If noxious weeds are listed on the tag, take into account that they could most likely become a problem in your pasture by becoming hard to control and outcompeting your desirable grass. NRCS also suggests that you purchase seed based on the Pure Live Seed (PLS) which you will use to calculate the amount of seed you will need for planting. Their calculations are as follows:
You need to determine viability first.
Viability = germination + hard seed + dormant seed
The second step is to calculate the amount of Pure Life Seed (PLS).
PLS = (%purity x %viability) / (100)
Finally, to calculate the amount of seed needed for planting. . .
Bulk seed/acre = (lbs. of PLS recommended per acre) / (percent PLS)
Seed inspectors visit dealers regularly to spot check seeds. During checks, inspectors take random samples of bags to have them analyzed for accuracy by NCDA&CS Seed Lab. If there is a discrepancy in the sample versus its label, a “stop-sale” notice is issued until the seed is brought back within standard and meets the label claims. Inspectors and dealers usually work together to make sure that consumers are being supplied the best seed possible.
Now that you hopefully have a better understanding of seed tags, go ahead and start shopping around for your spring pasture needs. For more information, please contact your local Agriculture Extension Agent.
Englert, J.M. 2007. A Simplified Guide to Understanding Seed Labels. Maryland Plant Materials Technical Note No. 2. USDA-NRCS National Plant Materials Center, Beltsville, MD. 3p.
Ferguson, J.M., et al. 2017. Seed and Seed Quality. AG-448. NC State Extension. Raleigh, NC. 29p.