On Wed, 25 Jan 2006 20:45:05 -0500, James wrote:

I know the 1/3 "rule" is supposed to be a real "rule", but it never
made much sense to me. If I followed it (never have) my lawn would
never ever look mowed.

For me, I try to never cut more than 80 % at one time.

The 1/3 rule (really a suggestion) is more or less to keep you from
creating thatch. If you let the grass blades get long then hack them down
short, the sheaf on the blades will toughen and thicken. This is what
gives your lawn a "woody" feel to it when you walk on it.

The other reason for the 1/3 rule is the when you mow off more than this,
there is a big reduction of nitrogen stored in the blade...ie removed. The
grass blade has to rebuild it's store of nitrogen, thus a heavy pull of
nitrogen from the soil. Doing this a few times a season will not cause
major harm to the lawn, but repeated hacking will cause thatch and
chlorosis.

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