I spent this morning (August 28, 2009) with Dr. Karl Guillard, a professor at the University of Connecticut who, among other things, is researching types of lawn grasses that require smaller inputs of water, fertilizer, and pesticides. He has been a key figure in the University’s “Fescue to the Rescue” program.

One of the primary goals of this program is to protect the quality of water in local waterways, aquifers, and Long Island Sound by reducing the amount of fertilizer spread on lawns: When washed into drains by storm runoff, turf fertilizers serve as a major source of water pollution.

Fine and tall fescues both flourish with a fraction of the fertilizer required by bluegrass. If you use a mulching mower and leave the clippings in place when you mow, the standard recommendation for a fine fescue lawn is to apply no more than a pound of nitrates per 1,000 square feet of lawn annually (the recommendation for bluegrass treated this way is two to three pounds annually). However, my own experience matches that of Neil Diboll of Prairie Nursery, a longtime promoter of fine fescue lawns who has found that except on the sandiest soils, these grasses need no fertilization at all. In sum, by minimizing the need for irrigation and fertilization, fine fescues protect water resources in two ways.

Dr. Guillard alerted me to another threat to the environment posed by lawn fertilizers. As the nitrates in fertilizers break down, some go to feed the grasses, but much escape into the atmosphere as nitrous oxide. According to a study published in Science, a leading scientific journal, nitrous oxide is emerging as the leading threat to the ozone layer in the upper atmosphere.

The ozone layer plays a critical role in protecting living creatures from the sun’s harmful ultraviolet rays. I have not been able to obtain any explicit figure concerning the amount of nitrates applied annually to turf in the United States, but a moderate estimate would put it in the neighborhood of 750,000 to a million tons (more, incidentally, than the farmers in India apply to all their food crops). The environmental cost of this is all the more painful when one considers that most of this fertilizer would be unnecessary if we simply converted our lawns to grasses better adapted to the local climate and soils.

Todd Forrest, NYBG’s Vice President for Horticulture and Living Collections, points out that fine fescues offer a couple of other potential benefits. They are more shade tolerant (the Botanical Garden’s shade mix is more than 90 percent fine fescue), and they are disease resistant.

He has also reminded me that for the home gardener, there is another, simpler option, which is what is popularly known as the “freedom lawn.” This is a lawn in which the gardener doesn’t discriminate, tolerating the presence of any low-growing green plant that can be cut by a mower blade. This survival-of-the-fittest philosophy typically results in a greensward that does fine without fertilizers or irrigation, and generally shrugs off pests and diseases.

This isn’t a bad option if you don’t mind a patchy look. However, a freedom lawn does require far more frequent mowing than a fine fescue lawn to keep it under control. I haven’t mowed my patch of fine fescues in six weeks, and next year I plan to mow it only once, just to remove the seed spikes when they appear in June.