If you grow hydrangeas you will know that they come in a variety of colors ranging from blue to pink and often you will not know which shade you will get. In the past traditional gardening advice has suggested that burying iron nails around the plants would persuade them to change color. Now there is a more scientific answer. I found an article on hydrangeashydrangeas.com which explains how you can achieve a color change.
Hydrangeas are fascinating in that, unlike most other plants, the color of their flowers can change dramatically.
It would be nice if one could change the color of hydrangeas as easily as it changes in this little picture. But for most of us, it is not easy. The people who have the most control over the color of their hydrangeas are those who grow them in containers. It is much easier to control or alter the pH of the soil in a container than it is in the ground.
On the other hand, hydrangeas often change color on their own when they are planted or transplanted. They are adjusting to the new environment. It is not unusual to see several different colors on one shrub the next year after planting.
It is much easier to change a hydrangea from pink to blue than it is from blue to pink. Changing a hydrangea from pink to blue entails adding aluminum to the soil. Changing from blue to pink means subtracting aluminum from the soil or taking it out of reach of the hydrangea.
That said, I’ll give the best information that I have on this subject and let you take it from there.
*COMMERCIAL GROWERS OF GREENHOUSE HYDRANGEAS (and others interested in this subject), SEE NOTE AT BOTTOM OF THIS PAGE.
HYDRANGEA COLOR CHANGE:
- WHITE HYDRANGEAS can NOT be changed to pink or blue by the grower. (The Almighty sometimes adds pink and red to blooms as they age).
- If you live in a hot climate, it is unlikely you will ever see a “true red” hydrangea. No matter how convincing those pictures in the catalogs are or how much lime is added to the soil, one can only achieve a very deep or dark pink, but not a true red (at least here in the South. I’d love to hear from you if you have a different experience).
- One can rarely change the intensity of a color (how strong or pale the color is). The intensity develops for a number of reasons: the heredity of a particular hydrangea variety, weather conditions (hot or cold, humid or dry), health of the plant, and possibly other natural factors. Fertilizing hydrangeas once or twice a year may result in a little more saturated color simply because the health of the plant may be improved.
- A few varieties of hydrangeas tend more toward the pink or the blue range of colors, but will not retain even this color if soil conditions are not right.
See more at hydrangeashydrangeas.com/