Seeding for Success

March 1, 2001

When you’re buying seed for an erosion control or hydroseeding project, it’s a good idea to know what’s in the bag. The easiest way to find out, of course, is to read the label. Labels give a generally accurate indication of what’s inside a seed container. Nonetheless, prudent buyers – especially of the more expensive native grasses, for example – will check out the contents first before making their purchase.

“I think it is important to know the quality of every purchase I make,” says Lee Daughtry, director of the Mississippi Department of Agriculture’s State Seed Testing Lab. “That’s just the way I am.” Daughtry, and others like him, insists on testing any seed purchased from a supplier, no matter how reputable the supplier might be. This is especially true for specialized seed used for reclamation and erosion control, even if the seed has already been tested, he emphasizes. Daughtry maintains that it’s simply good practice to know what you’re getting, and the only way you can really be sure, despite state and federally mandated labeling, is to have it tested.

“If the product you plan to purchase does not fit your needs, why would you want to buy it?” asks Charles G. Dale, manager of the seed laboratory in the Laboratory Services Division of Minnesota’s Department of Agriculture.

He acknowledges that the first step to making sure you’re getting what you pay for is to check the label. But if you want to play it safe, there’s a lot more you can do to protect yourself. “To make sure you can trust the truthfulness of the label, talk to the seller, friends, and neighbors about their experience with the seed labeler and seller. If suspicions still exist, ask seed regulatory staff to obtain an official sample.”

Labels are required by state and federal laws to provide accurate information about the origin, use, and value of seed. Labels, in fact, are carefully regulated precisely because of the critical protective data they contain for the buyer: name and address of the labeler, lot number, kind and variety of seed in order of predominance, percent by weight of pure seed of each species and variety, germination percentage, percent by weight of other crop seed, percent by weight of weed seed, percent of undesirable grass seed, percent by weight of inert matter, and the date when the germination test was conducted.

The label is designed to assure purchasers of the kind and quality of seed, as well as noxious weed content, which in the world of native grasses and reclamation projects can mean the difference between success and disaster. Labels are the first and most obvious safeguard for ensuring quality seed. Nonetheless, problems with labeling and poor seed quality arise for a variety of reasons, including unscrupulous suppliers, improper or substandard storage, inaccurate or dated lab tests, and just plain human error.

Despite the inherent risks of buying seed for specialized and expensive projects, however, most buyers have enough built-in protections – state and federal regulations, reputable seed dealers, lab testing, and personal experience – to prevent disastrous results.

Reputable Suppliers

The first consideration when buying “safe” seed is finding a supplier with a solid track record. “I protect our clients’ interests and companies by buying quality seed and working with reputable dealers,” states Wayne Erickson of Habitat Management Inc. in Centennial, CO, which specializes in reclamation and erosion control projects. Finding those dealers comes more easily when you’ve been in the business for a while and you have an established relationship with your suppliers, he adds. You learn quickly who can be trusted and whom to avoid.

“I’ve worked with a number of seed dealers over the years and know whom to go to,” he asserts. The suppliers who sell poor-quality product don’t last in this business. “You can’t afford to sell cruddy seed. Everybody knows everybody, and if you start selling junk, it won’t be long before your reputation precedes you.” Ron Schreibeis of Rocky Mountain Reclamation in Laramie, WY, agrees: “Suppliers who don’t offer pure, quality seed simply go by the wayside.”

It’s more likely than not, therefore, that a supplier who’s been in the business for a while can be depended upon for quality seed. Finding a reputable dealer “is not as hard as it sounds,” reassures Minnesota’s Dale. “Most seed companies are reputable, so it boils down to finding out what they offer in both goods and services and then deciding which one fits your budget and needs. A reputable company will usually be willing to give you a reference that could be checked for past performance. Start early and check as many as you feel is necessary and then compare.”

The best way to choose a reputable seed company, offers Don Bermant, owner of Granite Seed in Lehi, UT, is to consider the reputation of the supplier. Ask around, he advises, and get a list of references from the company itself. “Willingness to stand behind the expected performance of the seed is important. Most, if not all, seed companies will do this willingly because they want to preserve their good name.” Mississippi’s Daughtry agrees: “Ask the company for its customer list. You can talk to companies that purchase from them on a regular basis and ask questions. If the company refuses to give this list to you, shop elsewhere.”

There will always be the occasional unscrupulous seller whose seed doesn’t match the standards of the labels. Says Schreibeis, “Many tricks can be played by seed companies to provide less than the best-quality seed and stay within the specifications. If you buy a lot of seed or have an important project, I recommend you contact a consultant or someone who deals daily with seed mixtures and hire them to assist you with obtaining the best available seed and also assist with assuring that you are using the correct species for your specific project.”

If there are any doubts about a company, Daughtry also advises checking with the state Department of Agriculture to see if it has any violations. Especially for specialty seeds, he adds, “Remember that very few regulatory samples are pulled on these seed types,” and it’s imperative to get a supplier who can be trusted. Finally, Daughtry advises, “Ask competing companies about their vendor list. If the company you are looking at has few buyers, then something might need to be investigated further.”

When Should You Test?

Variations in seed quality will always exist, usually because of benign factors rather than intentional fudging by suppliers. This is particularly true for the more exotic seeds that make it hard to predict how a batch will turn out. Those factors can include test samples that are not really representative of the lot’s actual content, dated or inaccurate lab tests, or seed that has been exposed to unfavorable conditions during storage or shipment.

Because of these variables, another form of insurance when purchasing seed is to send a sample to an independent laboratory for additional, more current testing or resampling. At $100-$150 per lab test, it’s a small and worthwhile investment to ensure that the more expensive mix is going to deliver as promised, Erickson says. “If you want to make sure you’re getting what you paid for, you’d better get your seed tested. This is most essential with the more expensive, specialized mixes that erosion control contractors are likely to be using on projects where establishing biodiversity is one of the primary goals.” Especially with hard-to-get, hand-collected species that might cost as much as $70 or more per pound, Erickson adds, “You definitely want to be sure that you’re getting what you’re paying for.”

Granite Seed’s Bermant points out that it’s important to be aware of what you’re buying for two reasons: “to make sure you’re not planting unwanted seeds and to make sure you’re buying seeds of adequate purity and germination.” Granite Seed, for example, incorporates a quality-control program to ensure that all seed it sells is accurately labeled. “All of our seed is tested for purity and germination, using the procedures sanctioned by the Association of Official Seed Analysts,” claims the company’s Web site. The results and date of the test are reported on the seed tag, which shows the purity (percentage of the labeled species by weight); the percentages of other crop, weed, inert material, dormant or hard seed; and the percentage of seed by count that will germinate.

Because of Granite’s quality control and reputation, Schreibeis, a longtime customer who buys from numerous suppliers, hasn’t had to depend a great deal on outside lab testing. He’s confident because of the lengthy associations he has with his suppliers. “We rely most of the time on the information that they make available to us,” he states. He will, however, test seed he’s had in stock for a few months or when a client requests it. The Wyoming Department of Transportation, for example, regularly requests that seed be tested upon delivery to the project.

In some cases, Rocky Mountain Reclamation personnel have sampled seed provided by clients (as in the case of several coal-mine clients) to make sure the supply was in good order. This is particularly important when Schreibeis and his coworkers are not familiar with the seed company that a client has chosen to supply a project. During the recent reseeding of a coal mine, Rocky Mountain Reclamation required testing as a precaution, not being familiar with the seed company supplying the seed, Schreibeis recalls. In a few cases, he adds, both he and his clients were glad they did sample tests because the quality turned out to be less than acceptable. “We were suspicious about the quality of seed after we looked at it in our drill and after we had found out the price our client was paying. The tests came back within the legal limits, but the less expensive seed was near the maximum allowed and the expensive seed barely met the minimums. The established stand was witness to this a few years later, as there was an overabundance of the less expensive seed – more than our client wanted. Needless to say, that client will not use that seed company again.”

In another case in which a new client had seed in stock for a long time, Schreibeis ran tests and found significant drops in live seed for some species (even though most species held their germination pretty well), as well as significant amounts of weeds and other crop. One species had gone from the normal germination percentage to zero. “We were glad we tested the seed and didn’t rely on old information,” Schreibeis says. “By testing, we turned what would have been a potentially unsatisfactory stand into a great vegetation community with plenty of species diversity and excellent vegetative ground cover.”

When is it cost-effective to pay for additional sample testing? “Every time,” emphasizes Daughtry. “Testing for quality is the cheapest insurance you can buy. You get to pick the lab of your choice, which always is a plus for peace of mind. A lab you trust will always give you hard and honest data. You can’t ask for more. The only time I would not test again is if I knew the complete history of a lot of seed. Unless you are the producer of that seed, that is a rare occurrence.”

According to Dale of the Minnesota Department of Agriculture, however, “If the lot is uniform and stored under suitable conditions, testing needs are significantly reduced. It is usually a good idea to separate large amounts of seed into smaller lots to make sure uniformity can be guaranteed.” His guideline for buyers: “Anytime there are suspicions that the seed might not be truthfully labeled, it should be sampled and tested. A typical complaint occurs when the buyer opens the bag to dump into the planter and finds something that would appear to be wrong with the seed. Recognized weed seed is often a reason for concern, as is discoloration of the seed, indicating damage. Many states recommend saving an unopened bag of the seed as potential evidence if the seed fails to perform as claimed. Copies of invoices and labeling are also important.”

Schreibeis conducts additional sampling on “large projects where issues have been raised as to the quality of the seed and on small projects where seed establishment is absolutely critical. It is critical on all projects, but desires of clients sometimes require additional documentation of seed quality other than that provided by the supplier.”

One problem with resampling, though, is timing. When you have a project readied for seeding one day, measured for actual quantity to be seeded the next, and the project owner expects to have it seeded immediately, Schreibeis notes, there’s “no time for waiting days or weeks or months for test results before proceeding with seeding operations.” And while testing can prevent disastrous results and save money in the long run, it can also have a negative impact on labor costs if contractors aren’t careful. Waiting for test results can put a financial strain on a company’s budget. “Waiting might mean either mobilizing to another project at great expense or paying our people to wait on a project without working,” Schreibeis says.

Waiting for results might not be as much of an option in some parts of the country, he adds. “We have short seeding windows, and waiting a day or two may mean the difference between completing the project during this season or having to wait until the next seeding window.”

The Nature of Testing

Routine tests include a purity analysis to determine the extent of contaminants (noxious or common weeds and other unwanted seeds), purity of the desired seed, and germination rates. More specialized tests can be requested, such as tetrazolium testing, which quickly determines the viability of dormant seeds that are difficult to germinate. However, Dale warns, “Tetrazolium [TZ] tests are usually not recognized as an official method for determining viability because reading the results is so subjective. Seed analysts need a great deal of experience to read a TZ test result accurately and for the results to mean anything. The germination and hard, or dormant, seed percentages are the best indicators of potential performance of the seed. Overall, the variety, the pure seed percentage, and the germination percentage are the best indicators of value for seed.”

If you plan to test seed, says Richard Dunne of Wind River Seed Inc. in Manderson, WY, “Be sure you know the proper method for sampling or call a state seed inspector.” Dunne, writing for his company’s Web site, warns, “Red flags on a seed test would be absence of key species in a mix, especially the rare and expensive ones, large presence of cheap or unordered species, presence of noxious weeds, or significant deviations between advertised purity/germination and test results.. Tests are intended to be statements of probability and should be interpreted with care. If discrepancies appear on seed tests, ask the vendor for an explanation before you form an opinion.”

Indeed, variations in lab tests are more likely than not. Seed testing, while useful and generally an accurate rendering of what’s in a sample, is incredibly variable, remarks Bermant.

The factors in this variability include:

1. the sample of the seed lot. If someone calls for 1 lb. from a 5,000-lb. lot, it might not be a uniform sample. “We’re very careful when we see any inconsistencies in the field,” Bermant points out, noting that if there is a significant variation of a crop, it is harvested separately.

2. what happens to the seed sample upon delivery. Does it get overheated? Bermant recalls one case in which an inspector took a sample that later tested zero purity and zero germination. Knowing this was too irregular to be accurate, Bermant suggested that the inspector take another sample, which later tested above the standards indicated by Granite Seed. The inspector, Bermant says, apparently put the envelope in which the sample had been collected onto the dashboard of his car. Heat from the sun’s rays skewed the test results.

3. variability of results from lab to lab. One lab’s test results may vary significantly from another lab’s. Granite sells seed to the Bureau of Land Management, which sent a sample to a Utah state lab for testing. The test showed 80.81% purity, below what the label had indicated. A second test was run by a lab in Idaho and the result was significantly higher, 92.7%.

Tim Gutormson, president of Mid-West Seed Services Inc., a testing facility with 22 full-time seed analysts, points out that variations in testing occur for a number of reasons. First, there may be a lack of uniformity in the seeds themselves. Reclamation seed is not as stabilized or developed as corn and wheat, which test more uniformly, and reclamation seed has more dormancy and germination problems. This is especially true for native grasses, such as blue stems and Indian grasses, which are not as refined as wheat or corn. The native grasses are “not a material that’s very uniform,” Gutormson says. “There’s a certain percentage of seed that is mature and a percentage that is not.” Second, the samples themselves might not be an accurate representation. “There are good parts and bad parts of a field,” he points out. Finally, “There’s some subjectivity on the part of the evaluator.”

Costs for testing might be considered minimal when measured against the potential catastrophe of planting bad seed. “Purity tests can get pretty high,” Gutormson says. “Testing costs $20 to $40 an hour and can take as long as six to eight hours to complete. Noxious weed tests are about $15. A TZ test is $30, and germination tests range from $25 to $30 per hour.

The standards for testing seed are contained in the Rules For Testing Seeds, a publication of the Association of Official Seed Analysts, and in the Federal Seed Act regulations. “All seed laboratories follow, or at least should be following, these testing standards,” reports Dale. “They are recognized nationwide and have recently been amended to be in uniformity with international standards.”

International seed testing standards are overseen by the International Seed Testing Association. According to the American Seed Trade Association, “Seed is probably the most regulated agricultural commodity in the world.” Seed testing and certification standards “ensure the purity and authenticity of each variety as well as phytosanitary (seed health) standards to ensure that the seed is free of bacteria, fungi, and viruses” requiring quarantine. Although phytosanitary standards are of greater concern in international trade, they also apply to seed shipped within the United States.

Buying on a Pure Live Seed Basis

Most buyers agree that one of the best ways to ensure quality seed, in terms of both cost and purity, is to purchase only on a “pure live seed” basis. Pure live seed (PLS) is a measure used by the seed industry to describe the percentage of a quantity of seed that will germinate. PLS is determined by multiplying the purity percentage by the germination percentage, then dividing by 100. PLS is a way to standardize quality so that the purchaser can compare the quality and value of different seed lots.

Buyers and suppliers alike warn against being misled by the apparent lower cost of bulk seed. Buying on a PLS basis, even when it seems the cost per pound is more expensive, is the only way to calculate and fairly compare seed lots for a given plant species. “For a purchaser to adequately evaluate seed value, pure live seed prices must be determined before seed is purchased,” argues Dunne of Wind River Seed. “Seeds with higher purity and germination rates tend to have more vigorous, healthy seed than seed with lower PLS values. Also, higher-quality seed costs less to ship.”

“We encourage our customers to buy seed based on the pure live seed price, not on the bulk price,” Bermant agrees. He offers the following example: Lot A costs $1/lb., and Lot B is $1.50/lb. The difference in quality and cost can be shown by measuring the percentages of purity, germination, and PLS content for each lot.

Lot A: 75% purity, 60% germination,
and 45% PLS
Lot B: 95% purity, 80% germination,
and 76% PLS

As Bermant reports, “At first glance, Lot A might appear to be a better buy because it only costs $1 per bulk pound, whereas Lot B costs $1.50. The quality of Lot A, however, is poorer than Lot B.” To compare the value of the two lots, a buyer must calculate the cost per PLS pound, not bulk pounds. In this example, the cost of Lot A is $2.22 per PLS pound while the cost of Lot B is only $1.97 per PLS pound. Therefore, Lot B is a better value. Furthermore since Lot B has a higher PLS percentage, it is not necessary to plant as much material as would be required when using Lot A, and therefore Lot B may result in lower labor costs.


Suppliers and labelers are under no obligation to educate buyers on their seed purchases, although some will. Ultimately it’s the buyers’ responsibility, whether experienced or not, to make sure they know what they’re getting, stresses Erickson. In the end, the contractor is the one who must ensure the quality of seed to be used on a project.

If buyers aren’t sure, adds Dale, or if they’re not clear about the information provided by labs and labels, “They need to either hire someone who does or take the time to learn about them.”

In recent years, Schreibeis notes, he’s found few, if any, glitches in the seed quality he’s come to expect from his suppliers. Between knowledgeable suppliers, savvy clients, and his own expertise, he’s confident of the seed he buys and of its dependability for particular jobs. There are no hard-and-fast rules for selecting seed, he says, and each job has to be approached on its own terms. “Every project has unique characteristics. It really depends on what the client wants” – and on the contractor’s ability to make an informed decision.