Question
Hi Kenneth:

I'm about ready to start my lawn care for a half acre lot for the year - just had a couple questions pertaining to aeration. I have a ridng mower and was hoping to do this myself by buying an attachment to save money from having it down professionally twice annually:

1)Am I correct that I should dethatch first, then aerate?

2) Many attachments I've seen utilize spikes to aerate, rather than the plug type. Don't the spikes tear up the lawn? Are spikes ok?

3) If I do get an attachment with spikes, how far down should these spikes penetrate for proper aeration?

Thanks very much,
Dan Allen

Answer
1) if you have a thatch problem then de-thatch, otherwise just aerate. Dethatching first and then aerating is how I would do it.

If you have very aggressive grass (bermuda, st. augustine, etc) then dethatching is a good idea. The type which slices into the soil rather than gripping the thatch with "arms" is preferred.

e.g. if you have a southern lawn with aggressive spreading grass which tends to develop thatch, then both dethatching and aerating is recommended. otherwise just aerate.

2) core aerators are recommended because they physically removes cores of soil and deposit these on top of the soil. This eliviates compaction giving roots the possibility to expand. Also fertilizer, water can easily get to the grass roots and air exchange is improved (air exchange makes roots breathe).

spike aerators are better than nothing. they will not eliviate compaction, in fact, sometimes they will make it worse where the spikes penetrate. If your soil is very compact, spike aerating is better than no aeration, but core aerating is almost always better.

3) spikes should penetrate 3-4" deep in the soil.
If you find that spikes do not penetrate 3" deep, then place a weight on the deck of the attachment (to keep it low) and water the lawn a few days before aerating.
Note: do not aerate wet soil, especially clay soil.

Wet soil will clog the thines and even if you use spike aerators wet soil will become rock hard if you try to aerate it. E.g. aerating will have the opposite effect.

However, dry soil (especially clay soil) will be difficult, if not impossible, to aerate. Moist soils, such as those watered a few days in advance, are the easiest to aerate.

Good luck.