Aerate? Yes... Lime the lawn? Maybe

Email the author | Follow on Twitter
on November 04, 2006 at 5:54 PM, updated June 28, 2007 at 5:59 PM

By George Weigel/The Patriot-News

Q: My lawn service told me I need to have my grass limed and aerated. I cannot afford to have them do it. Can you give me advice on doing it myself? How do I know how much lime to use, and can I use a regular sprayer to do this? Should I be doing these things now?

A: You can do both yourself, but Iâ€™d want to be sure first that the lawn really does need lime. Lime is the main way to make your lawnâ€™s soil more alkaline (i.e. increase the pH reading) if itâ€™s too acidic. Did the lawn company do a soil test to determine how acidy things were? A pH close to neutral â€“ 7.0 on the pH scale â€“ is ideal for a lawn. If youâ€™re at that or near it, you wouldnâ€™t need lime. This isnâ€™t an automatic thing to add, and if you donâ€™t have a recent pH reading, youâ€™re just guessing. I was going to add lime several years ago to my lawn because I hadnâ€™t done it in a long time, but when I did a soil test first, the reading already was a little over 7. Adding lime when you donâ€™t need it is at least a waste of money, and it can be detrimental to the lawn if the soil is too alkaline.

An easy and accurate way to get a pH reading is to buy a do-it-yourself soil test kit. I like Penn Stateâ€™s kits, which are $10 and available at all county Extension offices and most garden centers. You take cores of soil from throughout the lawn, mix them together, and send a little bag of it off to the Penn State soil lab, and usually a week later youâ€™ll get back a report. Thatâ€™ll not only tell you if you need lime (or sulfur to make the soil more acidic) but how much to apply. If you need to apply lime, fall is a great time to put it down. But youâ€™ll want to use bagged granular or pelleted limestone in a bag â€“ not a liquid spray. Put it down with a regular lawn spreader just like you would granular lawn fertilizer. Donâ€™t use pulverized lime, which is a powdered form of limestone. This blows around like crazy in a spreader, and youâ€™ll look like Casper the Ghost by the time youâ€™re done.

Aerating is a good procedure for most lawns each fall. Youâ€™ll have to rent a machine that operates like a big lawn mower â€“ only instead of having blades, an aerate has a rotating drum with spikes that remove finger-sized cores from the soil. The idea is to create air space and reduce compacted soil by taking cores out and dropping them on the surface. (Itâ€™ll look like geese have had a pooping party.) Go over the lawn two or three times in different directions to aerate well. Itâ€™s best done after a rain when the soil is soft. Most rental companies offer aerators, but they arenâ€™t particularly cheap. Maybe you could recruit a few neighbors to share the rental to hold down the cost? You can also aerate in the early spring, but I think fall is better. Just do it before the ground freezes.