Hydrangeas should look stunning in summer as it is now their peak blooming period, but their flowers can begin to wilt or even turn brown if they are not protected from the heat. Hydrangeas are very sensitive to direct sunlight, especially in the harsh afternoon sun, and their petals can easily become scorched. 

This can put a lot of stress on the plant which can lead to the flowers fading so they do not last as long as they should, and too much heat can even affect the buds growing for next year. It also does not help that there are lots of hungry insects crawling around gardens at this time of year, and it can further put more strain on hydrangeas if slugs are eating away at their flowers. 

However, the gardening experts at Bloom Song have shared that there is a really simple way to keep hydrangeas healthy and deter slugs, as all you need are some leftover coffee grounds. 

They said: “Hydrangeas thrive when given the right nutrients, and one natural and readily available option is coffee grounds.

"Not only do coffee grounds enrich the soil, but they also deter slugs, which are common pests that damage hydrangea leaves and flowers.” 

It may seem strange, but the leftovers from a cup of coffee can add more organic matter to the soil and can hold a lot of water, which can help hydrangea roots stay moist even on really hot days. 

Hydrangeas love coffee grounds, which also help make the soil mildly acidic. Slugs, who hate the sharp scent, are less likely to eat coffee grounds. 

One of the biggest reasons gardeners like to feed their hydrangeas coffee grounds it that acidic soil can help turn their petals blue, which also helps improve their colour so you get much more vivid blooms. 

Coffee grounds also contain nitrogen, as well as small amounts of other nutrients which helps support plant growth and give hydrangeas a little boost at they might be stressed due to the summer heat. 

The expert said: “Coffee grounds contain nitrogen, potassium, and phosphorus, which contribute to overall plant health and vigorous blooms.”

How to use coffee grounds to help hydrangeas in summer

All you need to do is take one cup of leftover wet coffee grounds (around 115g) and place them in a gallon of water. 

Leave them to sit for 24 hours, and they use the solution to water your hydrangeas once every two to four weeks in summertime. 

Coffee grounds are a natural pest deterrent and can help hydrangeas stay healthy, but it should be noted that you need to use leftover grounds as fresh coffee is too potent. 

Hydrangeas only enjoy slightly acidic soil, and too much acidity can burn the roots and really harm the plant. However, most of the acidity is extracted during brewing which makes them safe for hydrangeas, but just be cautious.

Make sure to water hydrangeas thoroughly when using coffee grounds and only feed them every few weeks to get the benefits. 

Coffee grounds work as a simple amendment to the soil to give these beautiful flowers a boost, so they should last longer and stay healthy no matter how hot the weather is.