You can find soil pH kits at most garden supply stores or nurseries. Soil probes are the most accurate since they give a numerical reading instead of a color-coded key.
If you are using a chemical dye pH tester, don’t mix your soil with water. Instead, mix it with the solution that comes in the kit.
Don’t place your container directly in the sun, or it could heat up your sample and skew the results.
You can find aluminum sulfate at most garden supply stores. If your hydrangea is already red, it will be much easier to get it to a purple stage.
Lyme makes it harder for your hydrangea plant to absorb aluminum so it will become more purple.
Adding too much of your supplement at a time could harm your plants in the long run. It’s better to add them slowly over time to preserve the health of your hydrangeas. It can take 1 to 2 growing seasons for your hydrangeas to change color.
Red hydrangeas are much easier to change to purple since they mix with a blue color. Blue hydrangeas are harder to change to purple since they are already on the blue area of the color wheel. Although you can change the color of your hydrangeas, you can’t change the vibrancy of the color.
