Hydrangeas - Pink or Blue

‘Let’s Dance Rhythmic Blue Jangle’ 

Nothing does color quite like a hydrangea, with its giant spheres of colorful flowers. One of the most popular flowering shrubs, hydrangeas are a great choice to brighten up your yard. The beautiful colors found at Gertens are vibrant blue, pink and purple. Hydrangea macrophylla, or big leaf hydrangeas will change colors from blue to pink depending on what the soil pH is. 

Soil  

In Minnesota we have alkaline soil. That means if you plant a blue hydrangea without changing the soil pH it will gradually turn pink.  

Testing your soil 

Gertens offers two types of DIY test kits. The capsule test and the digital pH meter.  

• Capsule test - collect a sample from your planting site.  

• Dig down about four to six inches and collect soil from that depth.  
• Put the sample in the tester along with distilled water and powder from the capsule included in the testing kit.  
• Your sample will turn colors according to how much pH is in the soil.  
• Use the included color coded pH chart to determine your pH. 

• Digital pH meter is even simpler.  
• Push the probe directly into wet soil for about three minutes.  
• It will register pH levels on a scale of 3.5 to 9.0. 

Once you determine your pH you need to choose what color you want your hydrangea to be.  

• Blue hydrangeas need acidic soil. 
• Pink hydrangeas need alkaline soil.  
• Color intensity depends on the level of pH in the soil.  

• Blue blooms need a soil pH below 5.5.  
• Purple blooms need a soil pH between 5.5 and 6.5.  
• Pink blooms are produced with a soil pH above 6.5. 

Gertens carries several products that will change the soil pH.  

• If your soil is too acidic, add Rapid Lime to neutralize the pH for growing pink hydrangeas.  

• If you want to make your soil more acidic add Aluminum Sulfate to the soil for growing blue hydrangeas.  

Espoma products are an organic option for maintaining and changing your soil pH.  

• Espoma Organic Garden Lime turn hydrangeas pink. Espoma Organic Garden Lime is the finest grade of pelletized, dolomitic limestone available. 
• Espoma Organic Soil Acidifier turn hydrangeas blue.  

This can be a safer option than Aluminum Sulfate due to potential toxic levels of continued use. 

• Bailey’s Color Me Blue and Color Me Pink are also safe, organic and all-natural.  
• Color Me Blue uses elemental sulfur makes the soil more acidic. 
• Color Me Pink uses lime pellets makes the soil more alkaline. 

Seaside Serenade ‘Cape Hatteras’ 

Location, location, location 

When planting hydrangea, consider the amendments you’re using and how it might affect the plants nearby. 

• Keep your hydrangeas away from other plants to avoid having the soil treatments possibly burn them.  
• Consider growing your hydrangeas in containers. It is much easier to control the pH level of the soil and none of your other plants will be in danger from the soil amendments. 

• In Minnesota hydrangeas need 6 hours of sunlight in order to thrive.  
• If you want blue hydrangeas, do not to plant your hydrangeas next to a concrete walking path or patio. 
• Concrete often contains lime, which makes hydrangeas pink.  

Watch a video on how to plant your hydrangea here: https://youtu.be/2OITA_FKMas 

The experts at Gertens are always available to answer your questions!