Firstly, you should have the soil tested before you start messing and
guessing. If your soil is alkaline, put coffee grounds around your
plants.... or purchase sulphur, but you will need to know how much
correction is necessary to change your soil.

Jen

Tristan wrote:
: Hello
:
: We have a row of Gardenia's growing alongside a wall. I think that
: the lime from the mortar and render is leaching into the soil and
: making it alkaline. I was wondering what I should use to increase the
: acidity in the soil.
:
: Tristan