Help: Nephew's science project

[Monique Reed]

Some sorts of Hydrangeas can be made to flower pink or blue by manipulating 
the pH of the soil.  (Usually with aluminum salts, if I remember correctly.)

M. Reed


>I recall watching a "home & garden" show which discussed a flowering plant
>which either had reddish or blueish pedals depending on the level of a certain
>soil nutrient.  Any idea on the plant name? Also, does soil have a specific
>nutrient makeup and if so, what are the effects of each nutrient.  Any help
>deeply appreciated.  Please excuse my misuse of terminology.  Very "green" here
>:)