Soil3 organic humus compost is not only for vegetables and lawns, woody plants thrive in it too. A customer near our Orangeburg, South Carolina, farm sent the office ladies these pictures of his beloved hydranega flowers he grew in a garden bed amended with Soil3. He is right to be proud of his Hydreangea macrophylla (bigleaf hydrangeas) and we thank him for sharing his joy in his plants and our compost.
Hydrangea macrophylla Flower Color Manipulation and pH Science
The flower color of bigleaf hydrangeas change with soil pH. A low (acidic) pH produces bluer flowers while a high (basic or alkaline) pH produces pinker flowers. Composted material, including Soil3, is neutral in pH.
You may be asking, "what effect will the neutral pH of Soil3 compost have on the pH of my soil and my bigleaf hydrangea flower color?"
In acid soils, Soil3 compost will neutralize soil so that if you have a highly acidic soil and blue hydrangea flowers the pH will be raised and the flower color will be influenced toward the pink.
In alkaline soil, Soil3 will again neutralize soil, but this time it will lower the pH so that pink flowers colors will be influenced toward the blue.
We use the word "influence" because soil pH adjustment to alter bigleaf hydrangea color is more often done with acids or lime, rather than compost. The effects of working compost into your planting bed are a gentler and healthier than aggressive pH adjustments using strong additives.
Most gardeners enjoy both blue and pink Bigleaf Hydrangeas and accept whichever color the soil pH gives us. The first goal is health of the plant. By adding compost, the soil that sustains your beloved Hydrangea shrubs is improved and nurtured so it can bolster the most healthy Hydrangeas your garden has ever enjoyed.