A gardener has shared a simple hack she claims can make hydrangeas 'bloom better' and change their colour to a 'deepest blue' by adding a common kitchen scrap to the soil.
How Coffee Grounds Affect Hydrangea Colour
According to TikTok user Brittany, who goes by the username allegedlybrittany, coffee grounds encourage hydrangeas to turn blue by raising the acidity of the soil. This enables the plant to absorb aluminium more effectively, triggering the chemical reaction responsible for turning the petals blue.
In her video, posted to her 28,000 followers, Brittany showed her flowers side by side. Some had been fed with coffee grounds, while others had not. The caption stated: 'This is the difference between using coffee grounds and not. The deepest blue I've ever seen.'
Visible Results: More Blooms and Deeper Colour
Brittany began by showing the hydrangeas that hadn't been treated with coffee grounds. While they were undeniably attractive, they were noticeably smaller and lacking in blooms. The video then panned across to the other side, revealing the hydrangeas that had been fed with coffee grounds. These were a stunning shade of blue, ranging from lighter hues to deeper, richer tones. They were considerably larger too, boasting an abundance of blooms throughout her front garden.
The video garnered more than 145,000 likes and prompted a considerable response from fellow gardeners, who were impressed by the results.
Important Considerations for This Method
It's crucial to understand that this method only works on certain varieties, such as lacecap, bigleaf and mophead hydrangeas. Varieties like oakleaf or smooth hydrangeas, such as Annabelle, will never turn blue.
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 added: 'It adjusts the level of the soil's pH. Acidic soil promotes blue or lavender blue blooms, while alkaline soil encourages pink or red.'
