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9 messages
07/05/2013 at 19:07

Last summer my hydrangea had pink flowers - the year before they were blue.

I understand they become blue with increased soil acidity.

Can anyone tell me how to achieve this again?

07/05/2013 at 19:18

Aluminium sulphate - you can get it from garden centres. Iron nails etc. DO NOT work!

07/05/2013 at 19:18

The variety mainly determines the colour....a blue hydrangea remains blue,on acid soils and becomes redish purple on alkaline ones.  On alkaline soils red is the natural colour.

So. Was your hydrangea in a pot?  If so comditions may have changed....your fertiliser. Water. Compost??

Tnere is a "bluing" agent you can buy that helps Hydrangeas stay blue.  The old fashioned  method was to bury old iron nails ...or scatter them...around the plant

07/05/2013 at 19:22

The variety mainly determines the colour....a blue hydrangea remains blue,on acid soils and becomes redish purple on alkaline ones.  On alkaline soils red is the natural colour.

So. Was your hydrangea in a pot?  If so comditions may have changed....your fertiliser. Water. Compost??

Tnere is a "bluing" agent you can buy that helps Hydrangeas stay blue.  The old fashioned  method was to bury old iron nails ...or scatter them...around the plant.  They do work over time.

Do you know the name of your variety?  If it is a blue variety but your soil is alkaline you are destined to have increasingly pink flowers.  Do you know if your soil is acid?

07/05/2013 at 20:02

Verdun,  You may have literally hit the rusty nail on the head.

The hydrangea is in the soil next to an outbuilding which has a rusty gutter which leaked badly very close to the hydrangea, but then the end piece fell off the gutter so last year the water leaked out at the end instead.

The metal gutter is due to be replaced with a plastic one, so perhaps instead of taking the old one to the dump I'll just "plant" it next to the hydrangea.

I've no idea what variety it is. It's been here years and has been shades of pink through lilac to a light blue.

We have an acid soil, but the hydrangea roots are right up against the bothy foundations so it probably gets varying pHs depending on weather.

What is the blueing agent and where can I get it?

 

 

 

07/05/2013 at 20:03
07/05/2013 at 20:04

Hi Gold1locks. Sorry missed your reply. Is Aluminium sulphate the blueing agent Verdun mentioned?

07/05/2013 at 20:15

Yes.

07/05/2013 at 20:50

Thanks.

 

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