March 2008

Changing the Color of Your Endless Summer^®
The Original Hydrangea

St. Paul, Minn. (Spring 2008) – Bigleaf hydrangeas are unique in that their flowers can change color. Endless Summer The Original produces spectacular pink or blue blooms depending on the soil's pH and its ability to absorb aluminum at different levels. Alkaline soils will produce pink blooms. More acidic soil will turn your blooms blue.

If you’re planning to manipulate the color of your hydrangeas, here’s one word of caution: many people have killed their plants by applying too much of a good thing. More is not better.

Changing Flower Color
The first step is to learn the pH of your soil. You can buy a soil pH testing kit at most garden centers. Talk with garden experts in your area for soil testing tips.

Changing to Pink
To change from blue to pink you need to change from an acid soil to an alkaline one. Many soils in North America are naturally alkaline already and will product pink blooms with no extra effort required.

• To help raise your pH you can use dolomitic lime several times a year. You will have to retest your soil and aim for a pH of about 6.0 to 6.2. If it goes above 6.4 your hydrangea may experience an iron deficiency.
• Use fertilizers with high levels of phosphorus such as 10-25-10. Phosphorus helps to prevent aluminum from being taken up in the plant's system.
• Consider growing them in a large pot where it would be easier to control the pH.

Changing to Blue
Lowering the pH of your soil will produce blue flowers with a pH level of about 5.2-5.5. Using a soil acidifier will lower your soils pH for beautiful blue blooms. Tips for success:

• Ask the experts at the garden center where you purchased your plants what they recommend to acidify the soil in your area.
• Follow directions carefully on the product you purchase.
• Thoroughly water the plant before adding any acidifier.
• Don’t apply during the heat of the day.
• Remember to check the pH of your water. If you are trying to turn your flowers blue and you have hard water, it will be difficult to achieve. Also remember that concrete foundations and walkways tend to leach lime, raising the pH in that area.

Other Methods Include:

• Adding large amounts of organic matter, such as peat moss and composted leaves, will acidify as they break down.
• Applying elemental sulfur or iron sulfate. Sulfur works slowly. Iron works more quickly but requires more to work. Applied in recommended rates, it will be safe for your plants.
• Products like Miracid^® will help you maintain a lower pH once achieved.

Visit endlesssummerblooms.com for more information and beautiful, high-resolution images. We’ve expanded the content for both garden journalists and consumers to provide growing tips, planting ideas and ways to preserve these beautiful hydrangeas for lasting decorations. The site also features a retailer locator so your readers can find a garden center near them to purchase Endless Summer The Original and Blushing Bride.

Bailey Nurseries is a family-owned wholesale nursery with home offices in St. Paul, Minnesota. It is among the top wholesale nurseries in the United States and provides industry members throughout the U.S. and Canada with a full line of bareroot and container-grown plants from Bailey’s properties in Minnesota, Oregon, and Washington.