The more alkaline the soil is, the pinker the blooms will be – but a simple kitchen scrap ingredient that is acidic can help turn pink blooms into mesmerising blue and purple shades
Hydrangeas are among the most coveted flowering shrubs for their stunning blossoms and adaptability. The truly captivating aspect of these plants is the colour transformation potential they possess, particularly the switch from pink to entrancing hues of purple and blue.
On days graced by sunshine, or when the sky is clear, those blue and purple tinges can elevate your garden’s charm, creating an exquisite vista.
In particular, it is the hydrangea macrophylla variety, commonly referred to as the “bigleaf hydrangea”, that is celebrated for its colour-changing prowess. Bigleaf hydrangeas are recognised for flowering in pink, blue, purple, or white – each shade an invitation to splendour.
While the white will stay true to its hue, impervious to alteration, the other colours are at the behest of their growing medium.
The true alchemy behind transforming a hydrangea’s flower colour isn’t in treating the petals; instead, it lies within the soil’s chemistry, reports the Express.
Pink blooms flourish amidst alkaline soil, whereas flowers may still blush pink or begin to adopt a hint of blue along with delightful lavender shades in neutral pH environments.
Acidic soils, with a pH value less than 5.5, set the stage for blue hydrangeas, while soils hovering around a pH of 6.5 to 7 coax out the lilac and indigo tones of purple hydrangeas.
Hitting up Facebook, a lady revealed how she transformed her hydrangeas from plain pink to a mesmerising mix of blue and purple, crediting the magic to her leftover coffee – an effortless trick that only snatches 15 seconds from your day.
With a snapshot for proof, Christina Edwards exclaimed: “Apparently, my hydrangeas appreciate my morning coffee grounds. The multicoloured hue is due to the extra acidic soil from the coffee!”.
Curious commenters wanted the lowdown on her method, prompting her to explain: “Yes, coffee is acidic. The colour of the hydrangeas is correlated to the pH of the soil, and more acidic soils produce bluer blooms.
“I don’t add coffee every day, it’s at most three times per week.
“There are three bushes and they’re all outside, and eventually the coffee grounds decompose into fertiliser, and the rainwater dilutes the coffee.”
Describing her ultra-simple approach, Christina said: “I brew my coffee in a coffee press, so the grounds left at the bottom of the coffee press, I just pour them onto the soil! I don’t mix it in, I just let Mother Nature take care of the rest.”
It’s not just Christina reaping these rainbow rewards; other green-fingered folks chimed in with snaps of their own blossoms turning tantalising tones of blue and purple, thanks to the humble coffee ground hack.