Where's my blue hydrangea gone?

I bought a stunning blue hydrangea last year, potted it up in ericaceous compost and it gave me a long and fabulous display.
This year, I have been feeding it with ericaceous feed since it started to bud and it is growing good and strong. But, the flowers are just green with a hint of pink at the tips of the petals :(
They aren't fully open yet, but there's no sign of blue.
Can I get my blue hydrangea back, even if it's next year?

 

Hi Daisybelle,

Hope this link helps:

http://www.hydrangeashydrangeas.com/colorchange.html

It seems that colour change is not always a guarantee! Although this line gives some hope:

"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."

 

I can sympathise, daisybelle, as my intense blue one bought last year started off as pink this year but seems to be darkening. I'll post a pic in a couple of weeks.

Have faith .. if all else fails, put blue ink in the water you feed them with rather than buying expensive "bluing" stuff.

 

Oh, it's not fair. All the articles say to put in acid soil (check) and use a specialist fertiliser (check)
Is ericaceous fertiliser the same as a hydrangea bluing agent?

 

Well, after reading this article, I have bought some universal indicator and aluminium sulphate home from work today. The article gives a dilution, but doesn't say how often, just, 'throughout the growing season'. Any idea how often would be OK?
Thanks