* If you have a Kentucky bluegrass lawn and you see any shiny grass blades on a sunny day, the glossy blades are the "backs" of perennial ryegrass (which is bad news since perennial rye out-competes bluegrass). The one sure way of suppressing perennial rye is to set the mower to cut at one inch from spring to fall. The low cut helps bluegrass, but hinders perennial rye.

* Tall fescue: extremely wide leaf blades happen where the grass is growing without competition from weeds and such. You're likely to find wide blades where the grass borders a driveway or sidewalk.

* Tall fescue: new lawns should have little or no "foot traffic" for a full growing season so the grass develops a vast network of roots by year-end.

* Zoysia: leaf blades have hairs to the very top of the blade. Rest a leaf blade on your finger in sunlight and you will see the minute hairs.

* Zoysia: if you are developing a zoysia lawn, you must apply a granular pre-emergent to prevent crabgrass seeds from sprouting. Maximum sunlight is needed if zoysia is to develop stolons for increased coverage on the lawn. Crabgrass limits sunlight on zoysia, thereby preventing stolons from growing.

* Foot traffic on residential lawns should be held to a minimum. Compaction decreases moisture drainage and the movement of oxygen in the soil. Compaction increases the bulk density of soil. The last broadleaf weed to survive in compacted soil is knotweed.

* Sandy soil never compacts, regardless of the foot traffic.

* Aerifying residential lawns is productive because it increases soil density. Aerification should only be done before the greatest period of turfgrass growth, namely in late winter-early spring and in late summer. Don't aerify lawns at other times of the year.

* Air is 78 percent nitrogen.

* Water-soluble nitrogen (WS) is quickly absorbed by turfgrass, but only partly. About 50 to 60 percent of water-soluble nitrogen is absorbed by turfgrass roots, the rest is absorbed by organic matter and microorganisms in the soil.

* Despite commercial advertisements to the contrary, mushroom humus contains high amounts of salt, therefore it is a liability if spread on soil before applying grass seed.

* Organic fertilizers with high concentrations of protein release quickly as long as soil temperatures are above 53 degrees. Organic fertilizers perform better on acid soils (pH below 6).
 * f you overseed the lawn, reduce competition from existing grasses by mowing closely, generally 11/2 to 2 inches. If you de-thatch first with a verticut machine before overseeding, this gives a remarkable edge to new grass plants arising from the seed.

* Oxygen for photosynthesis on lawns is taken from water present in the grass plant, not from roots. However, roots absorb oxygen to live, but oxygen is converted from water for photosynthesis. When floods overrun a lawn, gaseous oxygen cannot be absorbed by roots, therefore they die.

* Finding footprints on your lawn isn't a good omen. Footprints mean the grass is in a water-deficit situation, and grass is in the process of dying. Deep-soaking the lawn is the timely cure.

* Naturally produced in some turfgrasses, the enzyme lignin is one reason why tall fescue lawns resist wear and tear. High concentrations of lignin are found in leaf blades of tall fescue. Insignificant lignin is found in blades of Kentucky bluegrass, so this explains why kids playing on bluegrass lawns isn't a good idea. The grass will suffer!

* Phosphorus and potassium have minimal roles in triggering diseases on residential lawns.

* Nitrogen or the lack of it is involved in disease spreading over the lawn. Lawns lacking nitrogen usually develop dollar spot, leaf spot, red thread, rust and anthracnose in the spring, then summer patch. Excessive nitrogen causes pythium, brown patch, and gray leaf spot.