The Amazing Colour Changing Hydrangea!

Last Updated on 29/04/2020 by Shannen Godwin

Hydrangea paniculata Vanilla Fraise. Pure white cones of flowers, gradually maturing to a delicious shade of raspberry pink and then to red in autumn.
Hydrangea paniculata Vanilla Fraise. Pure white cones of flowers, gradually maturing to a delicious shade of raspberry pink and then to red in autumn.

These big beautiful shrubs are hugely popular and why not? Lush broad foliage with huge clusters of flowers that change colour in different soils – what’s not to love! Most Hydrangeas like the morning sun and will thrive if planted in a shady or partially shaded area – especially the big leaf varieties.

The big bold “flowers” on the mophead are actually colourful leaves so in a botanical sense aren’t flowers at all. Beautiful to look at BUT not as useful to anyone creating a garden with wildlife in mind. For that you need the lace-cap varieties which are loaded with pollen so great for bees, butterflies and other useful insects.

Colour changes:

Colour changes in hydrangeas occur naturally as the plants mature – but the PH levels of your soil will affect blue and pink varieties especially the big leaf varieties.

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Simply put:


If the pH level of your soil is more acidic then Hydrangeas will turn blue, going mauve in neutral soils and pink in alkaline. (Neutral is pH 7.0)

Know your soils! – you can buy tests to check the pH levels of you garden soil from most garden centres OR if you’re lucky enough to be living next door to a keen gardener make friends with them and you might pick up a bit of local knowledge!

Hydrangea Mixed Collection Mophead 1005707

Urban myth or amazing fact?

Rusty nails will turn a Hydrangea blue!

Sorry but we couldn’t possibly go around dispelling advice passed down for generations here! However if you do decide to try this make sure you:

  • DON’T damage the root of the Hydrangea when you add your nails
  • DO plant the nails 8-10 inches away from the base of the Hydrangea
  • DO plant the nails at 8-10 inches intervals around the base of the Hydrangea
  • DON’T do it at all if you have inquisitive pets (or children) who might dig them up and hurt themselves!

Confusing fact!

White and green flowered Hydrangeas will generally keep their colour regardless of soil PH – although the pink and blue varieties that do change colour often will mature to white and green!

An easy way to keep your Hydrangea’s true to their colour is to grow them in containers or raised flower beds. Hard water from taps can also effect a change in colour so use rainwater to water your hydrangeas where you can. Saving and using rainwater has the added bonus of saving money on your water bills and being great for the environment!

Read more about creating an Eco friendly garden here.


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Hydrangea Change Colour Collection

A superb collection of two premium, colour changing Hydrangeas which really do make the ultimate statement in the summer garden, from July to October. You will receive one each of Magical Amethyst (lime-green and Pink) and Magical Revolution (blue and purple).


2 thoughts on “The Amazing Colour Changing Hydrangea!”

  1. My Hydrangea is flourishing every year but it has never flowered, I have no idea why and would appreciate if someone could give me some advise, maybe I am doing something wrong or it has to be replaced.

    1. Hi Alexander,
      Sorry to hear about you Hydrangea!
      The most common reason for not flowering is over-pruning or pruning at the wrong time. The best time to prune is after the flowers have died (they will look a bit unsightly for a while). Prune at the end of January or early February and make sure you are only cutting back the dead wood. [This is for Hydrangea macrophilia whose flowers bloom off last year’s wood so this will only apply if you have this type of Hydrangea.]
      You should also feed the Hydrangea with potash in spring – don’t use mulches with high levels of nitrogen as they don’t like that.
      The weather and location can of course also affect your plants.
      Deliberately vague there as we don’t know the specifics but do feel free to come back with a few more details if none of those seem right!
      Thanks for getting in touch.

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