Hydrangea pink to blue?

Can anybody recommend the best or cheapest way to turn my pink hydrangea to blue. The colourants in the garden centres are so expensive. Its in the ground. Ive looked online and it seem that maybe aluminium sulphate (iron free??) is a contender but looking on Ebay I could buy 1kg but would have no clue how much to use or how to apply it. Thank you.

 

My advice is to grow whatever suits your soil Cindy. Then you will have a settled happy shrub
It’s very difficult to turn pink hydrangeas into blue ....it is an annual task and very rarely does a pink variety become a true blue

What is your soil like? Alkaline or acid? Grow a named variety red or pink (or white) in alkaline soil for a beautiful plant. If you have acid soil a named blue variety would remain blue

 

Hello Verdon. thanks for reply. It was blue when I bought it and lost its colour when in the ground. Using the colourant worked last year but very costly. All I know is its a mop head???? Ball like flowers. No idea about my soil but I grow delphiniums. Roses. Geraniums. Phlox. Penstemon. Lupins etc and live on the south coast with quite a lot of clay in patches. My colour scheme is blue and purple with some red so really don't want pink.

 

It sounds like your soil is alkaline then cindy......buy a PH tester. Very cheap and very easy to use and it will tell you what soil you have. It will be a costly thing to apply colouring every year so......
Since your hydrangea is blue why not put it in a pot with ericaceous soil. It will then retain its blue colouring
How about going for a red variety for your garden? It will keep its red flowers then.

 

Have a go at tea leaves
They may well tip the balance to slight acid.
You will need to do it on a regular basis and I doubt it it would work for this year.
Just a cheap way of doing it.
I seem to remember using the aluminium salts some years ago
You need to start early in the season.
Trial and error, just don't over do it.

 

Ah thank you. Didn't know you could get red ones. Ive only ever seen pink or blue. Will give tea leaves a go this year and then maybe think again next year as to a pot and a new red one (if I can find one)

 

Not all hydrangeas will do this, first thing. second thing I buy the ones with the color already showing in the plant and don't worry about such things .

 

Hi Cindy, I use a colourant together with Water Butt water with a drop or two of Vinegar in a raised bed with ericaceous compost.

 

Cindy, there are excellent named varieties around these days but choosing a hydrangea to suit your soil will pay dividends. Some fantastic reds, many with coloured foliage too.
Years ago people used iron filings, tossed rusty nails etc into the soil to help “bluify” hydrangeas.
By all means try some of the suggestions offered but the principle of growing plants suitable for your soil is the best way to go I think
In many parts of Cornwall here blue hydrangeas thrive in the acid soil. True clear blues with not even a trace of purple
Consider the white hydrangeas too.....these are unaffected by alkalinity. And the paniculata types, my personal favourites.

 

Consider using vinegar to change the color from pink to blue. This will acidify the soil. If the soil already contains sufficient levels of aluminum, the hydrangea will be able to uptake the aluminum and the blooms will change. This is best controlled using pots but you can try it in the ground. I have been amending the soil of a lacecap to turn the blooms purple.

 

Thanks everyone. cant help it but really really really (a lot) want blue/purple. Will try everything including some vinegar. If all else fails I will have to dig it up and put it in a pot next year.

 

The only truly effective way to have a true blue hydrangea is to do 3 things Cindy
Buy a named blue variety
Plant in acid soil
Try to avoid tap water
However, let us know how you get on

 

Ok I use the colourant, and use Vinegar in very small quantities only in a raised bed.