Hydrangeas will bloom beautifully blue if watered with 1 natural item

Spring is the time of year when gardens start to come back to life after the long winter and it's a great time to add in some fresh plants to add a splash of colour.

are a great choice for this as their striking flowerheads come in an array of interesting shapes, including balls and cones, and they bloom in . The popular shrubs are ideal for planting in spring as the soil is warm and moist which creates a good environment for the plants to get established. The then tend to come into bloom from mid-spring until late , although this can depend on the variety and the growing conditions.

If you're a fan of the blue variety then there is a very easy way to help maintain that striking bright colour throughout the spring and summer, and that's simply by watering the plant with rainwater.

Gardening experts say that while hydrangeas can be watered with tap water, it is best to use rainwater instead, particularly if you want beautiful blue flowers.

Tap water - especially in hard water areas - can be alkaline and this can cause blue-flowered hydrangeas to turn pink. But rainwater, by comparison, is naturally more acidic and it is this acidity that helps hydrangeas to produce blue flowers.

Gardeners' World explains: "Water regularly, even weekly if necessary, throughout the plant's first growing season to help the roots establish.

"Water hydrangeas with rainwater to help keep the flowerheads blue. Hydrangeas do best in moist soil and can wilt in hot weather, so be ready to give extra water during hot spells in summer, especially if they are in full sun."

The type of soil you plant hydrangeas in can also affect their colour, so if you want a bloom colour you'll need an acidic soil with a pH of 5.5 or lower.

Scotland Grows adds: "To encourage blue hydrangea flowers, grow the plant in soil that has a pH of 5.2-5.5. If the pH of your soil is naturally higher and therefore alkaline, it will be very difficult to get blue flowers. You can, however, lower the pH of the soil by applying an acidic organic mulch, such as pine needles, pine bark, sawdust, or oak leaves.

"Coffee grounds are also slightly acidic if your local coffee shop lets you collect them. Alternatively, you can buy a commercial soil acidifier at your local garden centre or nursery.

"Another tip is to use rainwater to water your hydrangeas, since water from a mains tap can affect the flower colour, turning blue flowers mauve or pink.

"Remember though that even if you purchase a blue hydrangea in bloom, you cannot be sure that the plant will produce the same colour of flowers once it is growing in your garden if your garden soil pH is too alkaline."