A TikTok gardener has revealed that adding a common kitchen scrap to the soil can make hydrangeas “bloom better” and turn the “deepest blue”. Brittany, who posts under the username allegedlybrittany, shared a video with her 28,000 followers demonstrating the dramatic difference between hydrangeas treated with coffee grounds and those left untreated.
Striking Results From Coffee Grounds
In the clip, Brittany first showed hydrangeas that had not received coffee grounds. While they were an attractive colour, they were lacking in blooms and appeared small, according to the Express. She then panned to the other side of her garden, where hydrangeas had been treated with coffee grounds. These flowers were a stunning shade of blue, with some lighter and others deeper. The blooms were considerably larger and more numerous throughout her front garden.
The caption of the video read: “This is the difference between using coffee grounds and not. The deepest blue I've ever seen.” The video garnered more than 145,000 likes and prompted an enthusiastic response from fellow gardening enthusiasts.
How Coffee Grounds Change Hydrangea Colour
Coffee grounds help transform hydrangeas blue by raising soil acidity, which enables the plant to absorb aluminium. When soil is acidic and low in pH, the flowers can readily absorb aluminium from the soil, triggering the chemical reaction that turns the petals blue. It is crucial to understand that this trick only works on certain varieties, such as lacecap, bigleaf and mophead. Varieties like oakleaf or smooth hydrangeas, such as Annabelle, will never turn blue.
Gardening Community Reacts
User Strawberri95 asked: “I've not heard of this. How does it work? Do you sprinkle the grounds on the soil at the bottom of the plant? Or mix it with the soil?” Beth Dunn replied: “Sprinkle and water would work. You can also pour old coffee on the roots. The acidity changes the bloom colour and makes them bloom better.” Alice Benson commented: “It adjusts the level of the soil's pH. Acidic soil promotes blue or lavender blue blooms, while alkaline soil encourages pink or red.”
Hydrangeas are beloved garden plants across the UK, coming in numerous different shades. When properly maintained, they can produce blooms for months on end each year. This simple kitchen scrap trick offers an easy way to enhance both bloom size and colour intensity.
