Grass seed facts

Since fall is the best time to seed, I am going to review the basic turf types and hopefully you will be enlightened enough to use this to your advantage in improving your own home lawn.  I have found that few people know how much seed to use, and they either put down too much or the wrong kind; perhaps even both!
In New England, we like to grow what we call “cool season” grasses which prefer temperatures in the 50’s to 70’s.  Anything approaching 90 causes heat stress resulting in browning or white sun scorch.  These grasses include Kentucky bluegrass, perennial ryegrass, annual ryegrass, fine fescue, tall fescue, and bent grass.  Within these grass types, there are many hybrid types, each with their own resistance to disease, drought, shade, insects, and ability to handle wear and then recover.
As you might expect, choosing the right grass seed is extremely important, especially when picking out a blend based on facts versus how pretty the package looks.  Bottom line, you pay for what you get when you buy grass seed.  If you buy cheap grass seed, you are likely purchasing old seed or annual grass which means come winter, your grass dies and you get to start over again next spring.
Kentucky bluegrass has great color, good density, but takes 21 days to germinate and only has fair wear and shade tolerance.  This is why planting sod that is comprised of mostly bluegrass in the shade is not a good decision because it will simply thin out and eventually need seeding with the right grass such as a fine or tall fescue.  Kentucky bluegrass has only fair wear tolerance, but compensates with good recovery abilities when injured.  Bluegrass creates thatch and requires regular aeration to keep in good health.  Kentucky bluegrass is a very small seed with over 1 million per pound, so while you only need 2lbs per thousand square feet, its small size and desirable characteristics makes its per lb price very high.
Perennial ryegrass works best when used in overseeding in an existing lawn since it works well with most other grasses.   Unlike bluegrass, both perennial and annual ryegrass have good wear tolerance but has a tough time recovering if damaged.  Perennial ryegrass seed is fairly large ranging in only ¼ million seeds per pound.  As a result, you need at least 8lbs per thousand square feet to seed your lawn versus 2lbs of Kentucky bluegrass.  Perennial rye is sensitive to cold winters and ice so be careful where you let snow build up along walkways.  Annual ryegrass is best used where erosion might be a problem and a quick cover is required, same for perennial as these grasses germinate the fastest of the bunch.
Tall and fine fescues are the last main grass types to review.  Tall fescue is great on sports fields, high-use traffic areas, and has good drought tolerance.  Tall fescue has a thicker blade but newer hybrids this is not as noticeable because certain home owners do not like the wider blade found in tall fescue.  Older varieties of tall fescue are often mistaken for grassy weeds in a manicured lawn because of their clump growth habit and wide leaf blades.  Tall fescue is the largest of grass seeds and again comes in at a little under ¼ million seeds per pound with the same seeding rate as perennial ryegrass.  Tall fescue does fairly well in shade, so if you have had trouble before, give this turf a try.
Fine fescue is a soft, thin-bladed cousin to tall fescue and is often well suited for partial shade or in a blend with bluegrass, as the two do well together.  Fine fescues come in a variety of names like hard, chewing, or even red.  Most do not like wet soils but can do well in dry shaded situations.  Fine fescue is not the grass to use alone in full sun or as a sports turf given its nonexistent tolerance to wear.  Fine fescue has under ½ million seeds per pound, so normal seeding ranges from 2-4lbs per thousand square feet.
Bentgrass is not considered a desirable turf in a home lawn due to its growth habit.  Bentgrass requires a very short cut to ¼ inch while most lawns require a 3” cut; such a low cut would promote a wonderful bentgrass putting green but ruin a normal lawn.  This is because bentgrass puts out leaves where it is cut, up top unlike other grasses which put up leaves from the base down at the ground level.  This different growth habit makes bentgrass ideal for golf course use but makes it a weedy grass in a home lawn, often found in small patches which appear lime green in color with brown stems.
In general, each of the grasses above is best used in conjunction with each other in specific blends for optimum use.  By evaluating your lawn’s growing environment, it is much easier to pick an appropriate grass blend which will do well once planted.  The key lies in the percentage of each specific grass in a given blend.  While you can buy any of these grasses alone, you can find great blends which are suited to some of the conditions described such as play, shade, or full sun.
Most grasses you will find in a hardware store are found in specific blends or by name.  The key to finding the right grass varieties lies on the label where they are listed by percentage of the mixture.  Just liking reading a label in the supermarket, you have to read the label in order to determine what you are actually buying.  Purchasing a grass blend just because it says “patch mix” or “play blend” can be misleading and may actually get you the wrong grass for your situation.  Only by reading the label on the blend can you properly tell what grasses you are actually buying.  In general, you get what you pay for when it comes to seed pricing so don’t skimp on quality or quantity!
In my lawn program I use six different blends of grasses with each containing four to five specific grass types. This is necessary to meet the variety of lawn applications such as overseeding and complete lawn installations while keeping in mind the specific site requirements.
Choosing the right grasses is very important for long term success of your lawn ecosystem.  Failure to over seed this fall, in order to add more turf to a damaged lawn system, can mean the difference of a great lawn in 2013 or just surviving.  Given that New England has experienced a record setting heat wave this past summer, it makes solid agronomic sense to plan on some kind of seeding in the fall of 2012.
Address the weak or damaged spots in your lawn this fall before its time to carve the turkey dinner, because by then, it’s all stuffing!