Hydrangeas and roses give two of the most beautiful displays in gardens when in bloom with their vibrant flowers.

As with most plants, adding fertiliser can be worthwhile as it can help them grow stronger, especially when it comes to roses.

Feeding your roses will encourage strong, healthy growth and abundant flowering, claimed the experts at David Austin Roses.

While specific fertiliser can be bought for both hydrangeas and roses, gardening pros at Gardena recommend making your own.

They argue that if gardens want an “abundance of colourful flowers” in their garden this summer, “fertiliser is a must”.

The pros added: “Using a homemade natural fertiliser, you can help your plants truly flourish and take pleasure in your gardening success.”

They noted that hydrangeas and roses “respond particularly well” when given a sprinkling of coffee grounds.

The experts explained: “Used coffee grounds are a well-known miracle plant fertiliser.

“This is due to their high content of nitrogen, phosphorus, minerals and potassium, which make them a high-quality natural fertiliser.”

Another benefit is that this kitchen scrap attracts earthworms, which loosen the ground and supply the soil and plants with nutrients from their excrement.

What’s more, this type of fertilisation “doesn’t even require a lot of effort”. Simply collect old coffee grounds, spread them on an old newspaper and let them dry out so that the coffee grounds can be spread more easily. 

How often you should use coffee grounds to fertilise a plant depends on the type of plant. 

Hydrangeas and roses that are planted in the ground can be fertilised with coffee grounds up to four times a year. 

The “best way” to do this is to lightly sprinkle the coffee grounds on the soil surrounding the plant and then gently incorporate them into the earth.

The coffee grounds can be mixed in with the potting soil when planting hydrangeas and roses that are potted. Any leftover coffee grounds can be thinly spread across the compost.