How do I stop blue hydrangea flowers turning pink?
Our Advice
Treat your plants with Hydrangea Colourant from Vitax or Sequestered Iron Plant Tonic from Doff. They contain powdered alum, which enriches the soil with iron and magnesium and encourages the flowers to stay blue. They can be added to the soil and mixed in or applied as a solution in a watering can. Use rain water whenever possible.
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