Purple hydrangea flowers

If gardeners want blue flowers, they often add aluminum sulfate [AI2(S04)3] or sulfur to the soil to reduce the pH to 5.5. For people who prefer pink, lime (a base) is used to bring the pH to 6.5 or above. Occasionally, a hydrangea bush will produce purple flowers. This color is difficult to obtain, however. Purple flowers only come about when the pH is between... 

Figure 3.2 A hydrangea bush s flowers turn blue if it is being grown in acidic soil the flowers are pink if the soil is alkaline, or basic. Purple flowers grow in soil that is in a narrow midrange between acidic and basic.

Many gardening books will state that the acidity of the soil affects the color of certain varieties of hydrangeas. The soil pH affects the availability of aluminum in the soil and thereby indirectly affects the flower color. A low pH or acidic conditions will yield blue blooms pink blossoms will be favored by a higher pH or alkaline conditions. A purple color is the result of a more moderate pH level. Potting soils with a high level of peat moss will produce blue hydrangeas. Areas... 

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See also in sourсe #XX -- [ ]

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