"White spots" on flagstone (landscaping, live, patio)

[gljohnsen]

We live in Gilbert, AZ. Professional landscaping was completed on our property in Oct, 2007 with flagstone installation on our patio and other areas of our corner lot. We are starting to see "white spots" on some areas of the flagstone. We have not yet contacted our landscaper. In the meantime, has anyone had similar experience? What is the reason for this and the solution? Thanks.

[wit-nit]

Sounds like efforvesence, which is salt buildup from wet soils around and under the stones. Comes with the heavy rains.
Google 'efforvesence' and you'll find numerous sites dedicated to the subject.