Expert: George Maxwell - 3/2/2008

Question
I am doing a science project involving pH. I have individual plants and need to know how to raise and lower the pH of them and their own little planter.

Answer
hi, and thank you for your question.

The normal method of doing this would be to add a set amount of acid or base to the water that you add to the soil in the planter. For example, you could add vinegar to the water of one plant, and baking soda to the water of another one. Provided you know:
a) How much water you give each plant
b) How much acid or base you put in each plant
c) The pH of the water whe you add it,

then you have as good basis for a project.

A word of warning though - some plants prefer acid conditions, and some prefer basic conditions, so if you find that , in your projects, plants grow better in acid conditions, that might not apply to all species of plants, and you should make that clear in your report. In general, plants that live in boggy environments tend to do well in acid conditions, because the decomposing and oxidising materials in a bog often provide acidic conditions.

Hope this helps.