Why hydrangeas change color

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, we'll give the best information that I have on this subject and let you take it from there. For hydrangea blooms to be pink, the plants must not take up aluminum from the soil. If the soil naturally contains aluminum, one must try to keep it away from the hydrangea's system. Following are a few tricks that might work: Add dolomitic lime several times a year.

This will help to raise the pH. Shoot for a pH of about 6. Since hydrangeas take up aluminum best at lower pH levels, raising the pH will help to keep the bluing effect of aluminum out of the hydrangea's system. Use a fertilizer with high levels of phosphorus. Phosphorus helps to prevent aluminum from creeping into the system of the hydrangea. In areas that naturally produce blue hydrangeas soils with aluminum , consider growing pink hydrangeas in large pots.

If hydrangeas are grown in pots, it would be best to use soil-less mixtures, since these mixes would probably not have aluminum in them. In a pot, it will be much easier to control the requirements for growing pink hydrangeas. To obtain a blue hydrangea, aluminum must be present in the soil. To ensure that aluminum is present, aluminum sulfate may be added to the soil around the hydrangeas. Important: Water plants well in advance of application and put solution on cautiously, as too much can burn the roots.

To make the aluminum available to the plant, the pH of the soil should be low 5. Adding aluminum sulfate will tend to lower the pH of the soil. Mix organic matter such as compost, chopped oak leaves, peat moss and coffee grounds into the soil to help lower pH. This is slow acting, but a good thing to do annually to maintain a lower pH around your hydrangea. Fertilize with high potassium, low phosphate fertilizer, such as Potassium will help increase aluminum uptake. Using ammonium sulfate as a nitrogen source in the fertilizer will also help to keep pH low.

But what if my hydrangea is purple? You Might Also Like: Four-Season Hydrangea Border Pink Hydrangea Garden Easy Flowers to Grow Colorful Backyard Border Grow hydrangeas in a container to change bloom color easier Raising or lowering pH takes time for additives to affect soil and is not usually permanent, so you must maintain the desired pH every year for the blooms to stay the color you want. Hydrangea color change tips: More intensely colored hydrangeas will be more intense after a color change.

In other words, if your hydrangea was a deep pink, it will be a darker blue. Do not add more amendments to get a darker color — it will not help and may cause problems in your soil. Use amendments according to package directions. White bigleaf hydrangeas will never turn colors no matter what the soil type, though some blush pink or even red as the flowers age.

Red hydrangeas are bred to be a deep, dark shade of almost-red pink not really a true red , so grow them in alkaline soil to get the best color. Changing soil pH is a slow process and must be maintained throughout the growing season to ensure your hydrangea stays the color you want. Published: April 1, Tags: shrubs soil special techniques. Acidic soil, which means a lower pH level, will yield blue flowers. You should purchase and use a specialist soil test kit to determine the pH of your soil.

Watering tips: 5 mistakes you might be making in watering the garden. You can do this by increasing the presence of aluminium. When you have blue flowers, you can turn them pink by removing the aluminium from the soil. Sprinkle around half a cup of garden lime for each 10 square foot area. Other things to remember when trying to change your bloom colours: White hydrangeas are not affected by the soil pH. This means they will remain white regardless of the pH level of the soil.

Hydrangeas fade naturally and dry in the fall. Hard water may also impact the flower colour so you should try to use rainwater instead of tap water where possible.

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