Turfgrass 101 by Scott Zanon

Published on

Turfgrass 101 by Scott Zanon with Comments by Dave Gardner


Every homeowner wants the nicest and best-looking lawn and to have their neighbors be green with envy. Living in the Midwest for the most part means that we have cool-season grasses to care for and nurture.


In our yards, turfgrass is the basis of a beautiful landscape. Keeping our lawns looking their best year-round is both challenging and difficult for sure. The hope for this condensed version of lawn care is that by gaining a little more knowledge, following the guidelines, and tweaking some management practices in your particular region, you too can have a healthy and viable stand of turf.



Good soil is a major component of having a great lawn. Six inches of good topsoil and some organic matter is a must. Most types of turfgrass thrive with a neutral pH so it may be prudent to have your soil tested.



In our regions, cool-season grasses both rule and thrive.

  • Kentucky Bluegrass – very popular creeping type that prefers full sun. Perennial Ryegrass – bunch type that prefers full sun and is high traffic tolerant.  It is the quickest to germinate and establish of our cool season grasses.
  • Fine Fescue (Creeping Red) – bunch type that is also shade tolerant
  • Tall Fescue (Turf Type) – bunch type that prefers full sun but will tolerate some shade and is high traffic tolerant 
  • Bentgrass – creeping type rarely found on residential properties that requires full sun and short mowing height


Kentucky bluegrass lawn
Kentucky bluegrass lawn




Watering deeply but infrequently enables development of a deeper and healthier root system that will help your lawn endure periods of heat and drought. If drought causes your lawn to go dormant, fear not as the grass will not die as long as the crown of the plant is still alive. About one inch of water a week during the active growing season is a good guideline and morning is preferable to reduce evaporation. Wise water use is a sure sign of a practical and thoughtful gardener.



Below are a few practices.

  • Keep your blades sharp and balanced and mow when the grass is dry (less clumping).
  • For early spring mowing, start early enough so that you can cut at a lower cutting height (2 inches) to remove dead grass blades and expose sunlight to the crown in order to promote faster green-up.  You should avoid scalping (see below)
  • A good rule of thumb - never “scalp the lawn” – which is to remove more than one-third of a grass plant in one mowing.
  • Change the mowing pattern each time you mow. Alternating the patterns causes more upright growth.
  • Bagging your grass clippings is not necessary. Mulched grass clippings left on the lawn add organic matter and even provide a small source of nitrogen. They do not promote thatch!
  • With the exception of creeping bentgrass, mowing your lawn at a higher cutting height has huge benefits. Taller grass allows for great photosynthesis and healthier stands of turf. It also shades out weeds and increases the drought and disease resistance. Our suggestion is 3 inches.
  • For the last few mowings of the season, cut the grass low again (2 inches) to avoid potential problems such as snow mold. This problem occurs in areas where winter snow cover is common.


Mowing height
Grass height may be measured with a Zanometer




It is a well-known fact that trees and turf do not get along well and is best to keep them separated. However that cannot always be the case. They compete for sunlight, water, nutrients, and ground space below surface level.


Shade can be the biggest obstacle when trying to maintain turf and trees together. Two somewhat incompatible plants are forced to coexist together and both are expected to perform optimally. It reduces the quantity of light available to turf and the length of time it is available. It leads to reduced turf density, increased root competition, and increased weed invasion. The trees reduce air circulation which can create additional problems with turf diseases. Shade is a major stress factor for turf.


Shaded, thin lawn
A shaded lawn is not a Zanon lawn


Despite their differences, turf and trees can peacefully coexist and even thrive together. Achieving that balance can be attained. Armed with an understanding of how each affects the other, decisions can be reached to modify the environment and maintenance procedures to optimize the growing conditions for both.


If after thinning, limbing-up, or removing trees and shade remains a problem, plant shade tolerant ground covers, perennials, or annuals in landscape beds where these will thrive.



An essential nutrient for all plants (including grasses) to survive and thrive is nitrogen. Let us not going to pontificate and tell you that you need to fertilize x times a year. What we suggest is do what you are comfortable with but stress the importance of late season fall fertilization. Below is one approach (Zanon )practices on his lawn with very successful results.


  1. Apply a fertilizer (slow release) application with crabgrass control between April 1-15. If you plan on seeding the lawn in the spring, do not apply the pre-emergent herbicide for crabgrass as it will inhibit seed germination.
  2. Between May 15-30, apply optional second round of fertilizer with broad-leaf weed control. This has to be put on grass that is wet for the herbicide to stick to and effectively control the broadleaf weeds. If you have few broadleaf weeds, we suggest you simply spot treat them or if you have none, just use straight fertilizer. If grubs are an issue, apply grub control now too.
  3. As your lawn may be starving by September 1, (Zanon) applies straight fertilizer.
  4. Around November 1, apply fertilizer with a high level of nitrogen. This is the most important fertilization of the year. If you choose to only feed your turf once a year, this would be it. At this time of year, the plant used the feeding to promote root growth all winter long. Another benefit is an earlier spring green-up.


Fall fertilization of turfgrass
Fall fertilization effects



  • In our heavy clay soils we are fans of core aeration every fall or every other fall in mid-late September. Besides helping to reduce compaction by allowing oxygen, moisture, and nutrients into the root zone, this also reduces thatch
  • Speaking of thatch, it is an almost impenetrable mat of intertwined and tangled grass on the ground surface. If you have a lawn primarily of older Kentucky bluegrass cultivars, you may have this problem. If so, dethatch the lawn with hand or machine-powered thatch removers and note that you will not need to do this every year. I suggest mid-late September.


Core aeration of lawns
Core aeration plugs



  • If you have large patches of the lawn that needs to be seeded/overseeded, please do so by mid-September for best establishment prior to winter. And remember to water and then water some more for best germination.