After determining that conventional fertilizers were not helping my lawn (and detrimental to the environment) I needed a new lineup of products to rehabilitate the soil. A few winters ago I came up with a plan based off what I knew about my lawn and gardens: the clay is close to the surface and the soil is alkaline (proven by the fact that azaleas and hydrangeas turn pink), and have followed it for the last two and a half years.
To improve the lawn and recondition the soil, I sought to remove the problematic weeds (dandelions, black medic, and creeping charlie), increase the organic material in the soil, and soften the hardened soil. The plan includes only a few inexpensive materials and produces strong results.
I begin in the early spring (mid April) by dethatching the lawn and then over-seeding with more grass seed (which I repeat again in September). This pulls up the thatch that his built up over the winter and allows grass seed and everything else added to the lawn to reach closer to the lawn’s root system. It also helps break up the root system of the creeping charlie. Not only are those optimal growing times for grass seed due to the temperature, but the amount of rain Chicago usually receives during these seasons also saves me on watering.
One of the main reasons for switching to organic products and methods was to improve the quality of the soil to support the grass instead of it remaining reliant on fertilizer. The soil in my lot is only a foot to eighteen inches deep before reaching solid clay. Instead of bagging, I have always mulched the grass when I cut, but still needed more organic material. Breaking up a spreading peat moss assisted in this while providing root base for new grass seed. Along with a manure/mushroom mix, it softened the hard areas that were the perfect breeding ground for black medic, and ended the slurping/suctioning sound I had come across.
In order to eliminate weeds (dandelions) I settled on two products. The first is a preventative, corn gluten meal, which, much like a fertilizer, I apply with a basic spreader in the spring, usually in mid May, and in the past also applied in the fall. While the results have not been perfect, it is certainly as effective as a conventional weed preventer. One other advantage is that it does not interfere with over-seeding.
When weeds do emerge, and they are too numerous to pull by hand, I use Avenger weed killer. This knocks out the weeds and they do not return for the rest of the season. Overall this year, I only had one set of dandelions emerge in late May, and haven’t had any problems since.
To further add organic material/food to the soil, I have added alfalfa instead of conventional fertilizer. I also apply this in late may, and then again in the fall. The easiest application for me is to use pellets with the same spreader I use for the corn meal gluten. The alfalfa fixes a bit of nitrogen to the soil, but not in the unnecessarily large amounts as in conventional fertilizer. Coupled with the clover in the grass, the soil has the right amount of nitrogen delivered in a way that the grass can use, instead of running off into local waterways.
A final product (recommended by a neighbor) that has helped is gypsum. While it may not work everywhere, it is effective in the Chicago region, and especially in my neighborhood where the soil has such a high clay composition. This is the final product I apply in late May. While it may seem like a lot to do all at once, it sets up the lawn for a healthy summer, and has eliminated the work until the fall. And, because it is all organic I don’t have to worry about any chemicals interacting with each other or overwhelming the grass.
While the lawn isn’t perfect (creeping charlie is still a battle), the black medic is basically gone (only a little growth along the sidewalk), and the grass is thicker, greener, and healthier. And my wife is happy.