What do hydranger plants need to stay red?

Question

Is it lime or acid?

Answer 1

It is much easier to change a hydrangea from pink to blue than it is from blue to pink. Changing a hydrangea from pink to blue entails adding aluminum to the soil. Changing from blue to pink means subtracting aluminum from the soil or taking it out of reach of the hydrangea--http://www.hydrangeashydrangeas.com/colo...

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Red Hydrangeas require alkaline soil. Aluminum is a component of all soils, but its availability to plants depends on the acidity of the soil.

  

Soil Requirements:   Well drained humus rich, alkaline soil. If you have acidic soil, add lime to acid soils to make less acidic.



I hope it helps.

Answer 2

I would suggest that you look up what variety of hydrangea you have to see if it actually does change colour. Some do, and some don't. But you are right about the acidity of the soil. Also, if its planted in the ground, make sure you research what acidity of soil in your area is common. It is must easier to control the acidity of the soil when the plant is in a pot.

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If this is your plant variety, then you need to have alkaline soil. But be sure of the type before you add anything to the soil. Good luck!