Grass Seed Basics

SHOPPING FOR SEED

When buying grass seed, you get what you pay for. Fortunately, every package of grass seed has a label, which is required to contain specific information. It must list the amount of five things that might be in that bag or box. First, there is the turfgrass, which is listed in percentage. There may be one or more species with several varieties of each. The next three are grouped in a general category of “other ingredients”, which may include weed seed, inert matter and crop seeds, also listed in percentages. Finally, noxious weeds, as determined by our state agriculture department, will be listed seperately, not by percentage but by numbers per pound.

Noxious Weeds - wild garlic, buckhorn, plantain and annual bluegrass. A top-quality seed will contain NO noxious weeds.

Crop Seeds - these can be more troublesome than noxious weed seed. It can contain seeds such as timothy, rough bluegrass, orchardgrass and bentgrass. Just 1% of these contaminants can produce up to 40 plants per square foot, and that can ruin the look of your lawn. A good seed mix should contain well below 1% of this.

Inert Matter - This includes chaff, hulls, stones and such. It will not harm the look of your lawn, but why pay for something that won’t grow? You want to have less than 3% in you seed.

Weed Seed - This includes common weed seeds that are not noxious. There should be none in your seed.

The Turfgrasses - They are listed by descending order by the percent present in the mixture (also called purity) and the germination percentage of each. Combining those two numbers gives you the real value. The real value is a good measure of the seeds’ quality. To determine the real value, multiply the percentage of contents by the germination percentage and divide by 100. Example; Let’s say we buy a box of “Merion” grass seed. It is listed as 90% pure and the germination percentage is 80%. 90 x 80 /100 gives you 72. 72 percent of what is in the box will germinate to “Merion” bluegrass, with the other 28% being other. To figure the real value of a mixture (different species) or a blend (different varieties of a same species), do the same procedure as above for each seed, add them together and divide and divide by the number of seed types.

Finally, when buying seed, look for a variety of names. Buy only named varieties and stay away from mixes that just list “common Kentucky Bluegrass,”, or “Tall Fescue”. These seed types will only lead to trouble. Last but not least, when you are shopping, remember your yards conditions (such as sunny, dry, moist, etc) and remember which seed types meet those conditions.

OVERSEEDING OR SODDING?

This is one question that you will have to answer yourself, but I do have an opinion. First, are you starting with an existing lawn or starting fresh? If it is a new or old lawn, have the soil checked for nutrient content and pH. This is one of the major problems with grass not performing the way it should. Simple soil testing kits can be purchased at your local garden center or home center. The pH should be in the 6.5 to 7.0 range for best nutrient availability. Now concerning seeding or sodding, my opinion is that seeding is better. Why? Because the grass that you seed is grown in your soil conditions instead of being grown in optimum conditions, which most of us do not have. Then there is the watering problem. Since the sod’s roots only go down 1 to 2 inches, it needs constant watering until it is established, whereas the seed’s roots start traveling downward from germination and is established quicker than the sod which means less watering. The sod is also fertilized heavily to get the desired growth and sale as quickly as possible. If you do not keep up with the fertilizer, the lawn will be like a drug addict going through withdraw. I always recommend seeding because it is less expensive and does better in the long run than sod. Now, if you are overseeding an existing lawn, there is a rule of thumb; if the lawn has less than50% turf, you are better removing the old and starting fresh. If it has more than 50%, overseeding is your route. The next table will help with your computations.

How much seed do I need?
Type of seed lb./1,00sq.ft - Time to germinate
Bentgrass 1 to 2 - Fast (7 to 12 days)
Kentucky Blue 2 - Slow (20 to 28 days)
Chewings Fescue 3 to 5 - Med. (10 to 21 days)
Creeping Fescue 3 to 5 - Med. (10 to 21 days)
Red Fescue 3 to 4 - Med. (10 to 21 days)
Tall Fescue 5 to 6 - Med. (10 to 21 days)
Perennial Ryegrass 4 to 6 - Fast (7 to 14 days)

Before seeding, remove any accumulated leaves and debris in the area to have a good seed-to-soil contact. After seeding, ruff the seed into the soil; do not just seed and walk away. Seed to soil contact is important! The key to seeding is to never let the soil completely dry out until the turf is 2 inches tall. Do not water deeply until the turf is established, and do not mow until it is 2 to 3 inches tall. Perennial ryegrass will be quick to cover, with 90% being covered in 5 weeks, while bluegrass can take until the following season to cover well. Be patient and let nature take its course.