david robery wrote:

can anyone give me some hints to help make my soil more acidic.

Dave, as Tim pointed out, adding organic matter and especially keeping
your soils heavily mulched will slowly reduce the pH and make your soil
more acidic and more friable.

Depending on what kind of clay you have, other chemical additives can
help, including sulfur and gypsum.

You need to check for an agricultural university website in your state
and search for "soil pH." Acidity isn't just an up-or-down-add-
more-of-one-component adjustment. You would be astounded at the quick
fix solutions you'll find in garden centers. This actually takes a bit
of research to find out the nature of your local soils. There are
detailed US Geological survey soils maps for some areas of the country,
for example. Some are available on-line. Once you know about your
soils, you can do a google search. Try things like "balance soil pH
California" or wherever you're located.

Another factor is the water you put on your soil every time you
irrigate. If you have water district water, you can find out the range
of pH of your water from the water supplier. Otherwise, you can easily
test pH with a pool testing kit.

If you want to be really official, you can do a soil test and get a
recommendation from the soils lab. Unfortunately, their recommendations
often include helpful suggestions like adding tons/acre.