rowland heights, ca
|How to change ph to acidic? Is there any product I can buy from home depot? If changed to acidic can I get blue color flower? thank you.
|Answer from NGA
August 22, 2007
|Hydrangea blooms color can be affected by soil pH. A somewhat acidic 5.5 should turn them blue, a more alkaline 6.0 should turn them pink with the effect being more intense the more extreme the pH. Pink and red hydrangeas often turn blue or purple in acid soils. Blue hydrangeas can turn pink in alkaline soils. Plants can be made (or kept) blue by applying aluminum sulfate to the soil; plants can be kept pink by liming the soil or applying superphosphate. Since your soil is probably alkaline, add aluminum sulfate to the soil in February or March and next summer's blooms should be blue.
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