Soil Compaction in Lawns

Soil Compaction, Over Seeding and Aeration

After a summer of kids and dogs pounding on the lawn and with temperatures dropping, fall is really the time to aerate and over seed the lawn.

Aeration is a process where holes are punched into the grass and ground allowing better gas exchange, loosening the soil and helping water floe to root zones. Though there are all kinds of gimmicky aeration devices, like the infamous clip on soles with 3” spikes coming out the bottom that you’re supposed to walk on your lawn with, only core aeration really is effective. Core aeration is a process where a cone like device pulls a soil core up and out of the ground as opposed to spiking the ground which has been proven far less effective in aerating root zones and dealing with compaction.

Compaction is a real issue in many lawns and an interesting, a piece in the New York Times on the lawns at Harvard showed that after a couple of years of compost tea applications, many compaction issues were relieved as microbial activity increased and broke down the elements contributing to compaction. A combination of aeration and compost tea are highly recommended for dealing with compaction issues.

While core aerating and turning up all that loose soil, over seeding at the same time will fill in those spaces made by the aerator, and the loose soil form the cores will help the seed to germinate. And sprout. Grass seed germinated and started out in the fall will come in much more strongly in the spring and be far less likely to fail in the heat of the summer than grass seeded in the spring.

If you have a particularly weedy lawn ( more than half your lawn is weeds) thanks to this year’s heavy moisture get rid of the weeds first either by hand removing or spot spraying weeds with a broadleaf herbicide. If the first application does not knock the weeds out, hit them again a week later. Wait at least one week after applying herbicides to aerate and over seed

By the way, herbicides are the antithesis of compost tea, they kill microbes in the soil contributing to compaction which favors weeds over grass. However, if you spot spray the weeds only you will minimize damage to the soil culture and by upping the compost tea, you can restart the microbial activity in these areas.

Comments are closed.