Don’t Bag Your Lawn Clippings
You’ve probably mowed your lawn several times already this year, but have you been bagging
your grass clippings? Let’s hope not. For many years homeowners have been under the impression that
removing grass clippings leads to a healthier and better looking lawn. In fact, it is difficult to buy a
lawnmower these days, especially a push mower, without a bagging attachment. These bagging
attachments are unnecessary and bagging your grass clippings can actually be detrimental to a healthy
lawn.
The biggest reason why people collect their grass clippings is because they believe that grass
clippings cause thatch. Thatch is a layer of undecomposed or partially decomposed grass roots, stems,
crowns, runners, and lower shoots that build up between the soil surface and actively growing turf.
Research at the University of Missouri indicates that grass clippings do not contribute to the formation
of thatch. Grass clippings are composed primarily of leaf material that is high in moisture, about 80 to
85 percent, and breaks down very quickly. Thatch layers will develop and dethatching should be a
regular part of any lawn maintenance program, but it is not because clippings aren’t bagged.
There are many other reasons why clippings should be returned to the soil. Grass clippings are
high in nutrients and contain up to 25 percent of your lawn’s fertilizer needs. Removing clippings leads
to a lawn that is nutrient deficient and needs fertilizing more often. Another reason is that yard wastes
such as leaves, grass clippings, and tree limbs have been banned from Missouri landfills since 1992. You
can’t put your grass clippings in the trash. Certainly grass clippings can be used as mulch or to produce
compost if needed but it is still better to return those clippings, and the nutrients in them, back to the
soil.
There are a few times when you may actually want to collect your grass clippings. Most mowers
come with the option of bagging, mulching, or side discharge but there are a few mowers that must
have a bagging attachment in place to be safely used. If this is the case, you should continue to collect
grass clippings. When a lawn is diseased it may be beneficial to collect grass clippings to reduce the
population of the disease or to prevent it from spreading. If a lawn is wet or excessively tall clippings
may clump together and cause lawn damage.
When you mow your lawn you should remove no more than one-third of the total plant height
and the resulting clippings should be no more than 1 inch in length. This helps to avoid clumping and to
encourage fast decomposition of lawn clippings. In the spring, when lawn growth is rapid, this may
mean mowing more often than once a week. Early spring (March and April) applications of fertilizer on
lawns will only increase the frequency of mowing. Your lawn may look beautiful for a while but
fertilizing at this time depletes the plants’ reserves and makes the lawn less tolerant of summer stress.
It is best to delay fertilizer application until May or better yet, October. For more information about
lawn maintenance, contact the Henry County Extension Center at (660)885-5556.