When establishing, maintaining, or improving your lawn, do you understand the differences between, and the purposes of, the lawn aerator and the slit-seeder?
What do these machines do, why do we need to use them, and when should we use one or the other or both? Let’s take a look at what your lawn needs in order to flourish, and then find out what these lawn maintenance machines do to help you help your lawn!
Grass seeds need direct contact with a good growing medium (the soil), as well as sufficient moisture in order to germinate. But this is only the beginning—once the seeds germinate, the plant roots need continued feeding from the soil nutrients and other supplements in order to thrive. Ongoing moisture delivered to the growing root zone is also necessary. Please see our article: How To Seed A Lawn
Many people think the purpose of the aerator is to simply poke holes into the surface of the ground over which you will then broadcast grass seeds. The seeds, they assume, will fall into the holes and later emerge as grass plants, sort of like digging a hole and inserting a bean seed into it in order to grow a bean plant. With lawns, this is not exactly how it works.
Running over your lawn with an aerator actually serves multiple purposes. The most obvious ones are to help alleviate compaction of the soil, to allow moisture (either from rainfall or from irrigation sources) to better enter the soil, and to allow fertilizers and other plant supplements such as lime to better infiltrate and mix with the soil, and to feed the grass roots at a deeper level in order to encourage stronger and deeper development of the root system.
Another purpose of aeration is to allow air to enter the soil to help carry out proper workings of bacteria that help break down organic matter on and in the soil. In this way, the grass clippings and the dead and dying grass plants or weeds and their roots will decompose and turn to humus which will actually feed the roots of the healthy lawn grasses. A sufficient amount of air is also necessary in order for the minerals in the soil to be transformed into forms that are usable by the grass plants.
Now, what does a slit-seeder do? Well, we don’t want to make this more complicated than it really is, so, here’s the answer—a slit-seeder slits the soil and drops seeds into the slits it makes! The machine has a series of rotating knives that operate in the same fashion as a reel-type lawnmower. These knives cut into the soil forming narrow grooves, the depth of which is determined by adjusting the machine. The hardness of the soil, usually related to the moisture content, is also a factor in how deeply the knives will cut. A small hopper mounted on the machine is filled with grass seed that is dispersed onto the soil at a rate that is determined and adjusted by the machine’s user.
So, that’s it—an aerator pokes holes into the soil to alleviate compaction, and to allow air, fertilizer, and moisture into the soil closer to the roots of the grass. A slit-seeder slices the surface of the soil and distributes seeds onto and into the soil. Okay, then, when should we use what?!
If you have a pretty good thick stand of desirable lawn grass already growing, use the aerator and follow up with a good program of lawn fertilizers. Also read: Numbers On The Fertilizer Bag
. As your lawn continues to thrive, aerate every year or two.
If your lawn is spotty, with some areas of desirable grass growing but other areas of thin or no grass, then use the slit-seeder. If your spotty lawn is also compacted or hasn’t been attended to in awhile, you might want to use both machines.
And, in the most severe case of all, that being a very poor lawn which has mostly weeds or very little desirable grasses on it, the best advice might be to just till up the whole thing and re-seed from scratch. That way, you can establish a nice lawn, and then keep it healthy with periodic uses of either the lawn aerator or the slit-seeder. Stay green!