Avid gardeners are always seeking easy, cost-effective tricks to enhance their gardens, and hydrangeas are a beloved choice in Britain for their vibrant blue, purple, and pink hues. Now, King Charles' former gardener Jack Stooks has shared a unique coffee hack to make hydrangeas bluer than ever.
Working with Coffee Friend, Stooks recommends adding a spoonful of coffee grounds to hydrangea pots during autumn. 'Coffee is great for acid-loving plants, such as hydrangeas,' he explains. 'If you want a really blue hydrangea in your garden, you would want to feed them these coffee grounds in the Autumn months. The coffee will be used as feed within the pots.'
Stooks, who worked at Highgrove for over two decades, also notes that coffee grounds can repel mosquitoes when placed in bowls near seating areas, attract worms to improve soil aeration, and serve as a natural fertiliser rich in nitrogen, phosphorus, and potassium. He suggests sprinkling grounds selectively in borders until all areas are covered.
Beyond the coffee hack, autumn pruning is crucial for hydrangeas to maintain size and shape. However, gardening expert Paul Parker warns that pruning at the wrong time can prevent blooming. He advises waiting until after summer flowering for uncertain varieties, and recommends pruning shrubby hydrangeas in late winter or early spring to protect new buds from frost.
Horticulture expert Ish also shares a beginner's tip: apply a thick layer of mulch—such as multipurpose compost, bark chippings, or shredded leaves—to protect hydrangeas from severe winter weather, as they benefit from insulation despite being hardy.
