French hydrangeas are admired for their globular blooms, which burst forth in gardens like fireworks displays in the late spring and early summer. Mopheads are normally pink, blue, or white, but if you’re ready to get your hands filthy, you can alter them to your preferred color.
The pH of the soil in which your hydrangeas are planted will determine what color of blooms they produce. The more acidic your soil is (pH less than six), the bluer your blooms will be, while more alkaline soil (pH over seven) will usually produce pinkish flowers. Even hydrangeas with names like Nikko Blue and Nantucket Blue, which can give you the impression that their color is a given, are subject to the pH level of their soil.
You must make sure that your soil is acidic if you want to assure blue blooms. There are fertilizers that can assist you in that endeavor, but other common components can be just as useful and less expensive. Introducing your used coffee grounds. Here’s all you need to know about using used coffee grounds to grow the bluest hydrangea flowers possible.
Which Hydrangea Varieties Can Produce Blue Flowers?
Selecting a cultivar that can yield blue flowers is the first step in realizing your dreams of growing blue hydrangeas. No matter the pH of the soil, the bloom colors of Oakleaf (Hydrangea quercifolia), Annabelle (Hydrangea arborescens), and Peegee (Hydrangea paniculata ‘Grandiflora’) hydrangeas will remain white or ivory. However, the game is on if you have French hydrangeas or lacecaps (Hydrangea macrophylla normalis).
How To Test Soil pH
You can get a kit from your neighborhood hardware or garden supply store to test the pH level of your soil if you haven’t already seen your hydrangeas through a bloom season. With the help of this clever technique, you may also try DIY:
Collect two plastic containers, vinegar, and baking soda to start. Using a hand trowel, place a few scoops of dirt into each container. Next, add half a cup of water to both batches of dirt to wet them. One bowl of soil should receive half a cup of vinegar. Your soil is alkaline if it fizzy. The second container should contain half a cup of baking soda. Your soil is acidic if that mixture fizzes or bubbles in any way.
What happens if neither mixture exhibits a reaction? The fact that your soil is neutral doesn’t necessarily mean that the experiment was a failure. Your soil sample leans closer toward the neutral end of the alkaline or acidic range if your bubbling or fizzing concoction just slightly reacted.
Keep in mind that even without adding an acid-booster like coffee grounds, if your soil is already acidic, you should be able to get some blue blooms. Hooray!
How To Change Hydrangea Color with Coffee Grounds
In the late fall, start incorporating coffee grinds into the soil around your hydrangeas. To help get rid of any unpleasant scent, sprinkle them about your hydrangeas, but make sure to incorporate them into the soil. Just twice or three times a year should be adequate to complete this process.
How Long Will It Take To Turn Hydrangeas Blue?
It won’t produce blue blooms by mid-afternoon if you sprinkle your morning coffee grounds on the soil of your hydrangea plant. It will take some time, and it will take longer if you have brand-new baby hydrangeas that won’t blossom for a few more years. The optimal time to start incorporating coffee grounds into the soil is in the late fall, many months before the blooming season starts. Repeat the procedure according to your regular fertilizer plan.
Your hydrangeas should reward your efforts with the most striking blue globes next spring with a little caffeine and a lot of patience. Just be ready to reveal your secret ingredient to the neighbors—they’ll be envious from the start.