Hydrangeas are flowering across Britain in beautiful hues of blue, pink, and white. While they require minimal care, nourishing them can ensure they flourish season after season. If you have pink hydrangeas and want to transform them into a stunning blue shade, there is one household leftover that works brilliantly as plant food.
How Coffee Grounds Change Hydrangea Colour
Hydrangeas shift colour depending on soil pH levels, and modifying the pH can prompt them to develop blue tones. This involves using coffee grounds, which increase the soil's acidity. Whether you use leftovers from your coffee maker or from a jar, both are effective, according to one gardener on Facebook.
Posting on the Gardening Hints and Tips UK Facebook group, John Baxter wrote: "You can use eggshells to try or add aluminium sulfate to the soil, but I tend to sprinkle coffee scraps. This doesn't just change the colour of my hydrangeas, but it also provides them with key nutrients. It took a while, but I swear by it now. They are a stunning shade."
Application Tips for Best Results
You can incorporate coffee grounds into the soil whenever it suits you, though a few applications during the blooming period work best. This could be one application in spring and one in summer, or every other month. Allow the grounds to dry completely before introducing them to the soil if they are damp, as moisture could encourage mould growth. Then simply distribute the grounds uniformly around the plant's base or work them into the soil.
The coffee grounds will not only alter the flower colour but also supply the plant with valuable nutrients. However, applying excessive quantities of coffee grounds to the earth can prove detrimental, so use them sparingly. Citrus peelings, including orange, grapefruit, lemon, and lime, can also be advantageous for hydrangeas and help turn them blue.
