Should I bag my grass clippings when I mow?

ASK THE HORT AGENT

Question Should I bag my grass clippings when I mow?

Answer While the answer is generally no, there are times when it may be helpful to bag grass clippings. There are two basic reasons people bag their clippings – to prevent thatch and remove unsightly clumps of clippings.

First, thatch is not a build up of grass clippings. Thatch is a build up of grass stems and roots. Clippings are over 75% water. Grass clippings are quickly broken down when they hit the ground. Thatch is more of a problem with warm than cool season grasses. The best way to minimize thatch is to fertilize correctly and aerate when the grass is actively growing.

Second, unsightly mounds or windrows of grass clippings will not exist if a lawn is properly maintained. Avoid excess fertilizer and mow at the correct height. Never cut more than one third of the grass blade off at a time. For example, centipede should be maintained at one inch. In order to do this, allow it to grow 1.5 inches tall, then cut off one half inch.

Mowing wet grass will also cause it to clump. Allowing the grass to dry before mowing will insure better distribution of the grass clippings and minimize soil compaction. Mulching and reel mowers chop up grass clippings very well. To prevent clogging up these types of mowers, it is important to maintain your lawn correctly.

Approximately one quarter of a lawn’s fertilizer need can be met by recycling grass clippings. This process is often called “grasscycling.” Can you imagine throwing those clippings away if they were in a bag labeled “fertilizer?”

On the other hand, there are a couple situations when you have to use the problem solving side of your brain (some folks don’t have a side, instead only a small portion). A disease outbreak is a good reason to bag your clippings. If you have a disease like brown patch, then bag your clippings and mow the diseased areas last. Hopefully, this will slow the distribution of the disease across your yard. Also, fertilize and water properly. There is a direct correlation between the severity of a disease and proper maintenance (fertilization, irrigation and mowing). The more incorrect your maintenance practices are, the more severe the disease outbreak will be.

Another potential reason for bagging your grass clippings is compost production. Many homeowners create compost piles by using clippings as a source of nitrogen and leaves as a source of carbon.

When making compost, avoid the use of diseased grass clippings. Brown patch disease (Rhizoctonia solani) is one of the most common turf diseases which should not be added to a compost pile. Ironically, the addition of compost without this disease may help to cure this disease in turf.

For more info on grass clippings and basic maintenance, visit http://www.turffiles.ncsu.edu/pubs/management/gc592.html If you don’t have internet access, call me at 910-893-7533 or email me at gpierce@harnett.org

Instead of a bag attachment, some homeowners need a hay baler. Be advised that talk of grass bales may attract the attention of the police department.

Gary L. Pierce

Horticulture Extension Agent

Harnett County