Xref: 127.0.0.1 alt.home.lawn.garden:3757

William Plummer wrote:

Most of the posts on this thread are calling limestone by the name "lime".
Lime is really Calcium Oxide and is very caustic and will lower pH a lot in
a hurry. Real lime is used in outhouses and to destroy the body after a
murder! We used it to mark the yard lines on the high school football
field.

What is being sold to gardners is actually limestone. This is typically
ground up seashells, Calcium Carbonate, Calcium Sulphate and the like.
These are very unreactive and if they lower pH, it will take a year for a
noticeable effect. But limestone is cheap. Buy lots. Apply it. and hope
for the best. It won't hurt.

But if you want a real reaction, buy real lime. Apply very carefully
wearing safety clothes! --Bill

the stuff here for lawns is brown and granular