The blooms of hydrangeas can be pink, white, or blue. Due to the pH of their soil, they come in a variety of colors, but you can use vinegar to turn pink-flowered hydrangeas blue.

If you don’t already know the type of hydrangea you have, you’ll want to measure the pH of your soil because if it’s too acidic, the bloom will never turn blue.

To start “blueing,” most hydrangeas need a pH level of 5.5 or lower. To make your soil more acidic, dilute 1 cup of apple cider vinegar into about 1 gallon of water.

With the vinegar solution, pour around the base of your hydrangeas, avoiding the stalk, stems, and leaves. Repeat every two weeks, and they should turn blue in a few months.

The best hydrangeas for color-changing blooms include Ayesha, Endless Summer, Purple Tiers, and Nikko Blue, so make sure you have the right kind of hydrangea before dousing.