Did you know you can change the color your hydrangea flowers bloom. Yep, you sure can. You may have noticed that they have changed “on their own” over the years, but actually the soil has changed, causing the color to shift. So, if you want to change the color, you can manipulate the soil, and voila, you’ll have a different color of bloom.
First, the color change only applies to pink and blue flowers. White hydrangea can’t be changed. Occasionally they will take on a pink tinge as the mature, but there’s really nothing you can do to force that. Sooooo, to change a hydrangea from pink to blue, you’ll need to do one of two things.
First, you can test the soil with a simple pH kit. If it is too alkaline, you will need to make it more acidic. To do that you can add natural organic matter to the soil, like coffee grounds, citrus peels, pine needles, etc. You can also purchase Aluminum Sulfate to increase acidity. The whole process will take a full growing season, so you will need to be patient. Basically, the plant needs aluminum to turn blue, but won’t be able to take up aluminum in the soil if it is too alkaline.
On the flip side, if you want to turn a blue hydrangea pink, you will need to add lime to the soil, to get a more alkaline environment. Turning blue hydrangeas pink is the trickier method, because if the soil naturally contains high levels of aluminum, it’s pretty dang difficult to change that. Again, it will take about a full year to get the colors to change. If, after one year, you haven’t been successful in with the blue to pink transfer, you may want to consider growing the hydrangea in a pot, where you can control the soil a little easier.
How cool is it that you can manipulate the color of your hydrangeas? It’s like going through a “blue period,” Van Gogh style, only in your garden.