Why Flowers Change Color

There are six main reasons why flowers change colors, according to Sherry Fuller, whose article appears on Swcolorodohome.com. One of those reasons is due to rootstock. When a plant grafts onto the roots of hardier relatives, this can result in faster growth for the plant. However, if the grafted part dies it leaves the rootstock, which is sturdier, to grow and that can change the color of your grafted flower. It can also affect the plant's abundance and the length of stems, particularly in roses. If you mulch roses well this can ward off this complication to some extent. Fuller recommends watering your plants if it is a dry winter because winter drought can cause roses, particularly those that have grafted onto another plant, not only to change color and lose their original characteristics but to die.

Stress can turn a human's hair gray, so imagine what it can do to a flower. Stress occurs when a plant is moved from one place to another and the result is that the flower can actually change colors, according to Sherry Fuller. For example, if a purple iris is transplanted and in the process is left out of the ground too long, when it blooms in the spring it may be white. Fuller notes that iris growers are perplexed by this occurrence and aren't exactly sure why it happens. Sometimes the flower color will return to its original color, sometimes not.

When a perennial dies out after a few years, it will leave seeds behind. The plants that result from these seedlings are generally more hardy than the plant of origin. However, the color of the flowers produced by the seedlings may be very different from the parent plant, particularly if the parent plant was a hybrid. Fuller notes that the columbine, in particular, is a perennial that routinely peters out after a few years but leaves behind seedlings that produce yellow or white plants.

The color of a flower can be changed due to the alkalinity or acidity of the soil that it is planted in. Hydrangeas will change from pink to blue depending on the soil's composition Acidic soil turns flowers blue whereas alkaline soil will turn the flowers pink.

Age takes its toll on flowers just as it does on everything else and that's why older bulbs are sometimes discarded because an experienced gardener knows that the worn-out bulb isn't going to produce the color of origin. For instance, gladioli may turn yellow and tulips may turn yellow or white as the bulbs age.

When the word "sport" is used in the gardening world, it refers to a flower color or leaf color or plant branch that has changed appreciably. Why this happens remains something of a mystery. It doesn't occur frequently but when it does a new type of flower or plant is created and it may feature unusual colors or form.

Flowers have natural reasons for changing colors but it has been discovered that their color of origin can be altered intentionally, according to Robert Griesbach, a research plant geneticist at ARS Floral and Nursery in Beltsville, Md. The color-producing pigments in flowers include the following: flavonoids, which are commonly found in roses and produce red and blue colors; carotenoids, which produce yellow and orange coloring and are present in marigolds and sunflowers; and chlorophyll, the third pigment, which gives plants their green color. Griesbach explains that through mixing and matching these three pigments, new colors can be created in flowers. In addition to creating new colors through the mixing and matching of these pigments, Griesbach also discovered that a flower's color can be changed by altering the pH or acidity level of the flower's cell or the soil. If you alter the pH in the cell of a rose the blood red petals could turn out to be pale blue.