Tuesday, October 16, 2012

Turfgrasses are Plants, Too

Turfgrasses have been utilized by humans to enhance their environment for more than 1,000 years, writes Dr. James B. Beard, an internationally recognized and respected turfgrass research scientist and co-author of "The Role of Turfgrass in Environmental Protection and Their Benefits to Humans." There is an extensive array of functional, recreational and aesthetic benefits of lawns. The more we mulch grass clippings in place and are thoughtful about how we care for our lawns, the more benefits we accrue.

After I posted "Plants not Lawns," I heard from turfgrass growers, their national association and a landscape company. One of them very kindly pointed out that turfgrass is a plant and, in fact, is classified as an ornamental nursery product by the Department of Agriculture. I have to admit that I thought of lawns as the equivalent of living carpets instead of as a durable and foot traffic-friendly groundcover plant. The average size of a lawn in the US is one-fifth of an acre. In a healthy lawn, there are six grass plants per square inch and 850 plants per square foot. I did the math: an average US lawn contains 7.4 million plants!

Turfgrass lawns provide many of the same functional and aesthetic benefits as trees:
  • Air Quality: Turfgrass traps and removes dust and dirt from the air. Just one acre of grass can absorb hundreds of pounds of fossil-fuel created sulfur dioxide in a single year. 55 square feet of turfgrass provides enough oxygen for one person for an entire day (that means my lawn provides oxygen for me, Barney, my adorable golden retriever, and at least one apartment dweller).
  • Carbon Retention: Lawns are a "sink" for carbon dioxide. Nearly a ton of carbon per acre per year is stored in the soil of golf course fairways and greens.
  • Cooling Effect: On a hot summer day, lawns will be 30 degrees cooler than asphalt and 14 degrees cooler than bare soil thereby reducing the need for air conditioning and the electricity required to power them.
  • A Natural Filter: Turfgrass reduces pollution by purifying the water passing through its root zone.
  • Controlling Soil Erosion: With its extensive root system, grass binds the soil, effectively absorbs rainfall and accelerates restoration of disturbed soils.
Northwest Garden Nursery’s beautiful gardens

Garden designed by Kip Nordstrom

Barney enjoying the cool grass
  • Noise Abatement: Grass plants absorb sound. If a grassy turf is planted on a barrier slope facing a noise source, the noise reduction can be as much as 8-10 decibels. Sounds that do penetrate lawn and tree areas are rendered softer and less irritating.
  • Aesthetic Value: Grass reduces glare, visual pollution problems and enhances the beauty of our surroundings.
The benefits continue to accrue. Dr. Beard writes with co-author Robert L. Green, turf grass "decreased noxious pests and allergy-related pollens; safety in vehicle operation on roadsides and engine longevity on airfields; lowered fire hazard via open, green turfed firebreaks; and improved security of sensitive installations provided by high visibility zones. The recreational benefits include a low-cost surface for outdoor sport and leisure activities enhanced physical health of participants, and a unique low-cost cushion against personal impact injuries...improved mental health with a positive therapeutic impact, social harmony and stability; improved work productivity; and an overall better quality-of-life, especially in densely populated urban areas."
A ribbon of grass in
Mary-Kate Mackey’s garden
Over watering and over reliance on chemicals can cause more problems than they solve. Experienced landscape companies can help homeowners find the right balance (meet landscape contractors and designers at the Yard, Garden & Patio Show, produced by Dennis 7 Dees, February 8-10).
A cool spot to relax
Lush, green lawns can be a landscape design tool to lead the eye around a space, set off ornamental plantings and provide a safe place for children, pets and adults to play. As I noted in my earlier post, I've noticed more people replacing lawns with other plantings and hardscapes, but I suspect most homeowners enjoy a grassy lawn somewhere in their gardens.

Sources: The Lawn Institute and Turf Grass Producers International.

1 comment:

  1. A good quality and well tended lawn sets off a garden wonderfully.

    Gaz: Alternative Eden