One major factor affecting plants is soil pH. pH is a measurement of the degree of acidity or alkalinity of the soil.
Alkalinity occurs naturally in areas with chalky soil and from high pH water. Soils that are alkaline (pH over 8.0) may be low in the availibility of the nutrients Iron, Manganese, Copper, Zinc and Boron. The soils may also suffer from poor drainage and may be more susceptible to disease. Plants that prefer acid soil can be harmed by alkaline soil.
Every plant has its ideal pH range
Below are some common garden plants with their optimum pH range. Plants are somewhat adapatable to changes in pH but grow best in a pH which is close to their optimum range.