On Jan 31, 7:02*pm, Vic Smith wrote:
On Mon, 31 Jan 2011 17:03:00 -0800 (PST), DerbyDad03

wrote:

What size dosage? A cup? A pound? 25 pounds?

What's a "regular interval"? Every week? Every month? Every quarter?

Right there I've got 9 possible sets of "repeated dosages at regular
intervals", but still no clue as to what is the optimum.

With all the "science" I've seen posted in this ng across a variety of
topics, I'm surprised no one knows the correct amount and time frame.

Probably because nobody here has used rock salt to kill roots.
When I had a sewer root problem I bought a root killer for that, can't
remember which one.
But there were instructions on the box (or bottle).

--Vic

root killer I have used with success
Roebic Root Killer K-77
they also make
Roebic FRK-12 Foaming-Killer-Concentrate