How to make hydrangea change color and the reason for color change

1. How to change the color of hydrangea

1. Aluminum sulfate: If you want to change the color of hydrangeas, usually to make pink hydrangeas bloom blue, we need to lower the pH value of the soil. You can use aluminum sulfate to adjust the color. When the hydrangea buds just emerge, take 2-3g of aluminum sulfate, mix it with 1L of clean water, and water the flowers once every 10 days. Usually, after 3-4 applications, the hydrangea will bloom blue flowers.

2. Blueing agent: When using aluminum sulfate to adjust the blueing, it is easy to misunderstand the timing and dosage of the blueing. It is recommended for novices to sprinkle a layer of hydrangea blueing agent on the surface of the potting soil when the hydrangea begins to sprout new buds in the spring. After that, as you water, the active ingredients will dissolve into the soil with the water, changing the pH value of the soil, thereby changing the color of the hydrangea. The blueing agent should be sprinkled once every 2 months.

2. Reasons why hydrangeas change color

1. The reason why hydrangeas change color is because of the change in soil pH. When the soil pH is 4-6, hydrangeas bloom in blue. When the soil pH is greater than 7.5, hydrangeas bloom in red. In the process of changing soil pH, hydrangeas will also change to different colors, such as purple and pink.

2. The reason why hydrangeas change color is not only affected by the pH value of the soil, but also changes with the blooming time of the hydrangeas. For example, pink or blue hydrangeas will slowly turn green until the hydrangeas are completely withered and decayed.