I'll make a general statement about hobby growers chasing any particular pH balance (a specific pH i.e.): You're chasing your tail. Unless you're ready to test frequently with equipment that is more sophisticated than the oft seen "plant store pH meter", your efforts will be frustrating.

That said, it is a good idea to use a nutrient supplementation program that encourages a lower pH (acid forming fertilizers or even adding acetic or citric acid to irrigation water) on acid-loving plants, and to add base elements to soils that appreciate a soil with higher pH (dolomitic lime e.g.).

A favorable pH level is necessary for a good nutritional environment for container grown plants, but not as critical as pH in mineral soils or in situ situations. Organic soils hold nutrients "more loosely" than mineral soils & our nutrient supplementation program insures that the nutrients are in solution & available over a broader range of pH.

If pH is too low or too high, it can hamper cell production. An example would be: high soil pH causes iron and manganese to become more tightly held and less available and also particularly hampers assimilation of many micro-nutrients. Low pH also influences nutrient absorption rates and can even cause toxicity issues (I'm thinking about aluminum being pyhtotoxic at low pH's).

Most containerized plants are reported to grow best in moderately acidic conditions- pH 5.5 to 6.0, but recent studies I've read have shown that many plants produce maximum bio-mass at pH levels as low as 4.5.

If the soil pH is too low, there are ways to correct it. Lime applications will neutralize acidity and raise pH. Dolomitic lime not only neutralizes the soil, but it also provides enough calcium and magnesium to support growth for the full growing period. Calcitic lime raises pH as well. It supplies calcium, but does not contain magnesium. Supplements of dolomitic and calcitic lime can only raise soil pH through liming- commercial fertilizers will not work.

There were a few thoughts, but by & large, I never worry about pH other than to think about whether the plant appreciates being in a little more acid soil or a soil that is a bit higher in pH.

Al