are one of the most popular flowers across UK . Known for their coloured halos of petals and sweet fragrance, they brighten up any flower bed.

From deep blues to purples and vibrant pinks, the flowers come in a variety of hues. However, maintaining them is extremely crucial. While it is well known that coffee grounds are a great way to help your grow, an expert has warned that it may not be as effective as you think for one crucial reason, reports .

Coffee grounds are reported to serve as an excellent fertiliser due to their high nitrogen content-an essential element for plant growth.

Nitrogen plays a key role in the formation of chlorophyll, the compound responsible for photosynthesis and nutrient absorption. It also contributes to the vibrant green colour of leaves and stems.

Additionally, coffee grounds are a budget-friendly choice. Many households already have them on hand, and for those who don't, they are available for purchase at Ocado for as little as £1.20. However, when it comes to hydrangeas, the benefits may not be as significant as often claimed.

warns that its impact has been overblown. They write: "There is a myth that coffee grounds will lower the soil pH to help acid-loving plants, like hydrangeas, grow.

"However, coffee grounds won't lower the pH significantly enough to make an impact. If you want to lower your soil pH, it's best to use a fertilizer designed to do this."