Issue 8, July 29, 2020

Choosing Grass Seed

How long does one take to purchase a new vehicle? It might take hours, maybe days or even months researching the features, comparing different brands, makes, models, engines, mileage, warranty, or test driving. The same thought and care should also be taken when choosing the seed for your lawn. Sounds crazy? It is not! This is the most critical investment in ensuring a high-quality turf that lasts.

When beginning your research for the right cultivars in the right place, checking out the national turf evaluation program is a good start.  The National Turfgrass Evaluation Program (NTEP) is designed to develop and coordinate uniform evaluation trials of turfgrass varieties and promising selections in the United States. Test results can be used to determine the broad picture of the adaptation of a cultivar. Results can also be used to determine if a cultivar is well adapted to a local area or level of turf maintenance.  These trials look at a variety of characteristics including color, disease resistance, drought tolerance, winter hardiness, traffic tolerance, and mowing height.  This is a great step in determining what cultivars will do the best in your lawn.

Now that a variety has been chosen it is time to find the seed. When choosing a bag of seed, the Federal Law requires that the label must contain the following information. The trick is to understand what is the most critical as it can make the difference between a turf that will last and one that will not.

  • Name of Seller- is just that, the same of the seller, and it is good to know if you choose to reorder.
  • Lot Number- This will allow for traceability should there be a problem.
  • Seed Variety and Crop Seed Content- Most labels will list the species present but most likely will name the variety as well. Be sure to check that the package does not state “variety not stated,” this means that it could be a species or cultivar that is not of the same quality. If Crop Seed Content on the label. This represents the percent by weight of all seeds identified in the container, which are grown as an “agricultural crop.” Agriculture grass crop species include redtop, bentgrass, timothy or orchard grass. These must be specified by name if more than 5% by weight. For example, if 1. 5% is bentgrass, this would equate to 135,000 bentgrass seeds per pound of the actual seed. Be sure to keep crop seed content as low as possible.
  • The date the seed was last tested- This is the date in which the seed was last officially tested. The older the seed, the more likely the germination percentage will decline
  • Purity Percentage- This is the percent by weight of each grass variety and kind. For example, if a seed tag lists tall fescue as 95% pure, this equates to 95lbs of pure tall fescue seed per 100lb of seed. A caution is that purity is not an indication of quality as not all pure seed is capable of growth or maturity.
  • Germination- Germination is the percent of pure seed that is capable of growth. This is determined under strict laboratory procedures within a certain time frame. It is critical to understand that since the conditions in the lab are near ideal, that if planting conditions are not ideal, then the percentage of seed that would survive will decline. The germination of seeds also declines with age. Be sure to check the date in which the seed was tested to ensure that the freshest seed is being purchased. Choosing the freshest and highest purity allows for the most excellent chance of high-quality turf. Both purity of seed and germination are components of seed quality and are used to determine Pure Live Seed (PLS). This is solved by the % of purity x % germination over 100. For example, the seed label states that the Kentucky bluegrass has a purity of 93% x 85% germination rate, this would mean that in a 100lb bag of seed that 79% is PLS. The percent that is closer to 100 would be a higher quality bag of seed.
  • Weed Seed – The is the percent of the weight of all seeds in the bag that have not been identified as either pure seed or crop seed. Ideally, this number should be as low as possible, since even the smallest seed could be a pretty significant problem.
  • Noxious Weeds- This is the number per pound of weed seeds. These weeds classified as noxious do vary by state. These seeds are considered undesirable because they can be challenging to manage, even with proven integrated pest management practices.
  • Inert Material- The percent by weight of all material in the bag that will not grow. This material may include broken seeds, chaff, soil, wood shavings, or empty seed hulls. Inert material helps to add weight to the bag but provides no real value to the seed quality.

Seed Labels on a Tall Fescue Blend Photo by Travis Cleveland

Seed labels might have a “blue” certification tag stating the product has been certified; this means that it has met specific standards of varietal purity. This certification only guarantees the authenticity of the variety. However, it does not imply any guarantee on the purity, germination, crop or weed seed content of the seed. Certification standards are more rigid; therefore, the percent of purity may be higher, and the weed or crop seed content should be lower. It is also free of prohibited noxious weed seeds.

Select seed based on the use of the area, evaluate the conditions of the area now and future use.  Once this has been considered and a variety chosen, it is time to purchase seed. Remember price is not everything.  Be sure to calculate price per pound of pure live seed this will give you a better idea of cost. The highest price seed does not necessarily equate to high-quality. Knowing how to read the numbers on the label and understanding the contents in the bag is what is critical for a lasting high-quality turf.

Maria Turner

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