Question
Hello!

I'm going to aerate my lawn with a commercial aerator that I will be renting. Since I have never  used one of these, do you have any recommendations?

Thanks!

Chris  

Answer
Hi Chris,
I strongly recommend core aerating. Core aerating will remove cores of soil from the ground and deposit them on the surface of the soil to decompose. The core holes will eliviate compaction which will introduct oxygen, water and nutrients (fertilizer) into the root zone. The decomposing cores will also bring microbes to the surface and help in the break down of thatch. It is one of the most recommended horticultural practices you can perform on your lawn.

First make sure you have the rental company demonstrate the use of the machine including how to start it (basically like a gas powered mower, but they will teach you where the chocke is, where to pull, which pins to push, etc). Secondly, make sure they demonstrate to you where the "dead man" switch is. This is typically a handle you need to keep depressed for the machine to run. If you let go, the machine stops. It is important that the machine has such as feature to avoid personal injury.

Make sure you bring a can of gasoline with you home also. While they rental company normally provides a full tank of gas, sometimes you can run out of gas, and at hourly rental prices you do not want to spend your time making gas runs. Also make sure you understand if it is regular unleaded it uses or which type of gas to purchase.

The machines are usually very big, heavy and bulky and having two strong people lift it can be very beneficial. alternatively a pickup or van with a ramp where you can wheel it up is recommended. It is very heavy.

Before you go to rent a machine like this, evaluate the soil moisture. If the soil is too wet (saturated) the tines will clogg. If too dry, the tines will not penetrate deep enough into the soil resulting in shallow cores being removed which reduces the effectiveness. If you have heavy clay, paying attention to core aerating with proper soil moisture is even more important as clay can stay very wet for a long time or alternatively be hard as brick when dry.

In most sandy loam or loam soil, you should water 2-3 days before core aerating. In spring when evaporation is less you can make this 4-5 days. Check with a screw driver. If you can push it into the soil to a dept of 4-6" then the soil is soft enough. If too wet, however, the soil can clogg the tines and it can be a mess to aerate. The weight of the machine can 'rout' the soil by making wheel tracks especially when you turn the machines at the borders. Therefore, letting the lawn dry a few days before is also a good idea. My recommendation is a moist lawn - not wet and not dry. It is not rocket science, but requires a little "gut feeling" to get it right. If in doubt, then I would say that as long as it is not very squishy or very dry you should probably be ok.

When you start the machine and activate the driving lever(the "dead man switch") the machine first lower the drum with the tines into the ground, and the machine will start to move just like a gas powered mower. It will pull and dump cores of soil at your feet which will make a mess on your shoes so use an old pair of tennis shoes. anything which wont have your wife make you sleep on the couch the next night is fine.

When you get to the end of the run make sure you DISENGANGE the handle so the tines LIFT up from the ground BEFORE YOU TURN. If you turn while the handle is enganged, and the tines are in the ground, you will rip up your lawn at the edge. Instead let go of the lever (usually inside the handle bar) which should raise the tines and stop the automatic forward propelling. Swing the machine around facing the direction you came from and re-engage the handle. The tines will be lowered back down and the machine will start to move again. It may seem obvious, by I always forget and end up ripping grass.

Another thing which I always forget and which is a p... in the b.... is to let go of the handle when you reach the end of your lawn. As long as you have the lever enganged, the machine moves. Repeat: as long as you have the lever engaged, the machine moves.

If you forget to disengage the switch (lever / dead mans switch) the machine will continue and not stop. First time I used one of these contraptions I was concentrating so hard that I forgot to release and the machine "walked" onto the road with me in full tow.. was darn near killed by oncomming traffic. Again, it sounds stupid (and probably was), but understand that the machine is pretty heavy and powerfull. It will pull you along and unless you are keenly aware and used to it you may not remember that the only way to stop it is to let go of the handle. It is probably only me who would do something like this, but still would like to mention it .. just in case ....

A few tips:
- now that you PAY to rent it, make sure you get your money's worth. If core aerated at the right times of the year (spring and fall for cool season lawns and summer for warm season lawns) it is virtually impossible to make "too many" holes in your lawn. If you have 1/2 hour left on your money, keep at it. Continue to make holes. The more, the merrier. Let the lunch wait to after you are finished. The lawn will benefit from being run over 2,3,4 times if you have the time.
- remember to disengage the lever when you turn (or you will rip grass).
- remember to watch for oncomming traffic (** ahhh!! **)
- after you are finished, wash the machine off with water and use a screw driver to dislodge any plugs in the tines. Dry it with a towel. This saves you the "hidden" $15 cleaning fee they don't tell you about. When you offload it at the store, ask for help to lift it down from the truck. Don't try to pull it off and drop it on the ground (they don't like it, I can tell you !! - and it will be more than $15 for this type of mistakes)
- fertilize the lawn after you are finished. this will bring fertilizer pellets into the core holes. This will also give a boost to the grass and help it fill in nicely (e.g. recover from the stress which core aerating really is).
- do not lime at this time. liming and fertilizing should not be done at the same time.


The cores.
I usually recommend to leave the cores on the surface to decompose. Depending on the foot traffic and the amount of rain, the cores will dissolve in 5-14 days. Initially it will look like 1000 dogs (or geese) did their business on your lawn, but eventually the cores will disappear. The decomposing cores are benefitial to the lawn. If you want to have some fun, when strangers are passing, stand at the street and shake your fist at the neighbors house while shouting "didn't I tell you to keep those dogs off my lawn ".. Just don't do it with the wife around, or you may find yourself on the couch (again !!).

She may even make you rake the cores if the sight is too offensive, and that is ok, too. Just rake them up with a leaf or soil rake and put on compost pile. You can also scatter them on your flower beds between perennials if you prefer.

Some people have reported the cores on the surface of the lawn have made "spots" in the lawn as the clay soil has smothered the grass. This seems to be a problem on heavy clay only. If you have heavy clay, it may be a good idea to rake the cores. It is usually not a problem, but some people have told me that clay soil cores can ruin a good lawn if left on the surface. I have never had this problem, but just so you know.

If you pay per half hour, just remember that 5 minutes late is usually equal to another 30 minutes charge, so add 5-10 minutes to your driving time to avoid this fee.

Good luck.
Kenneth