GreenYes Digest V97 #94 -Reply

Bill Carter (
Fri, 22 Jan 1999 16:53:22 -0500

Wayne Fenton writes:

I am looking for any available information regarding average grass
clippings generation rates, such as number of pounds per 'X' square
feet, per average residential lot, etc., over a growing season. I am
interested in data from throughout North America.

I would also like to find out about current management practices for
grass clippings (e.g., collected at curbside, banned from collection, etc.)
and estimated costs (per household, per ton) for whatever type of
program or service is offered.

I am not familiar with scientific data on generation rates of grass
clippings in Texas. If there are, the most likely person to know about
them is
Marty Baker
TX Ag Ext Service
PO Box 220
Overton, TX 75684
fax 834-7140
The primary management effort addressing grass clippings in Texas is
the "Don't Bag It" program developed by the Texas Agricultural Extension
Service about 10 years ago, which has more recently entered the public
domain under the generic term "grasscycling." It involves leaving grass
clippings on the lawn to decay into the turf naturally, and includes a set
of guidelines for adjusting mowing, watering, and fertilization practices to
optimize the self-regenerative contribution of grass clippings. We have
literature from the Extension Service explaining these principles, with
specific mowing-height guidelines and other recommendations specific to
each of a dozen sub-regions of Texas. There are outreach program
guidebooks including sample promotional literature and suggestions on
recruiting demonstration lawns in your community, etc.

There are many Texas cities that have Don't Bag It outreach programs.
We also have a statewide Master Composter program promoting Don't
Bag It practices as well as backyard composting and green yard care
practices, which also has a local outreach network active in many cities.
A few cities, notably Dallas, have implemented collection/disposal bans
on grass clippings -- some also ban leaves and light branches. Dallas
reported that total municipal waste collected in the first 6 months of the
ban (April-Sept 1993) was down 22% from the same months of the
previous year. This was partly due to dry weather, which reduced the
output of grass clippings, but that also indicates the significance of grass
clippings as a percentage of the city's waste stream. Two neighboring
communities implemented grass clippings bans at around the same time,
and their waste-collection reductions were comparable -- 21% to 24%
below the same months of the previous year.

There are many obvious factors that can cause the rate of grass
clippings generated to vary by location and year to year: degree of
shade, rainfall, length of growing season, fertilization practices, etc. My
observation in Austin has been that intensively managed 1/4-acre lawns
can generate 100-200 lbs of bagged grass clippings per week
throughout the active grass growing season, which are often over 40
weeks in many parts of Texas. Other same-size lawns which are rarely
watered, never fertilized, and never raked until the clippings are dry, may
generate one 5-lb bag every 2 weeks.

The Extension Service's Don't Bag It literature reports that one city of
18,000 homes estimated that the weekly set-out of grass clippings was
more than 700 tons. It gives a rule-of-thumb estimate that leaving grass
clippings on the lawn can provide "up to two pounds of nitrogen per
1,000 square feet" on an annual basis. It also states that grass clippings
usually contain "over 4% nitrogen." Those are some of the relevant
statistics I could find in a quick review.

You might also want to look into the Cost-Benefit Analysis of Home
Composting Programs in the United States, done by Applied Compost
Consulting of Berkeley CA for The Composting Council
( It includes estimates of yard trimmings diversion
attributable to backyard composting programs in a large sampling of
communities. One community cited in this study reportedly estimated a
diversion of over 2000 lbs/year per household that used grasscycling.

Bill Carter, Program Specialist
Texas Natural Resource Conservation Commission
Recycling Section, Office of Pollution Prevention & Recycling
MC114 P.O. Box 13087, Austin, TX 78711-3087 USA
(512) 239-6771