Blue Hydrangea

I love these colours :O)

What fertiliser/colour do you use for making it to bloom in blue?

Tea bags.
Rusty nails for pink. ;-)
GQT. Lol.

Hi Mouldy, tea bags for blue???

And what colour do you get from G&T???!!!
Katarina I use a Hydrangea colourant called Vitax on my blue ones but haven't used it this year so hints of pink are showing on some of them :o))

Thank you.

Yes, Katarina.
It's the tannin in teabags that effect the chemical change.
With rusty nails iron oxide does the job.

And when do you dig it around Hydrangea? And how many bags are required for the colour change?

I'm not sure, Katirina, how many bags or how much loose tea should be used.
I asked one of the city gardeners, about the different colours of the plant, in March just gone & that's all he told me.
I was curious to know why he was taking rusty nails out of a large jar of water & pushing them into the earth around the plant.
I guess the teabags should be applied at around the same time, when the plant is coming out of it's winter dormancy.
Sorry I can't be more helpful. :-(

This was interesting information. That about rusty nail I knew before, that one on tea bags was something new. Thank you for sharing it.

I just hope it works, Katarina.
I can't see why it shouldn't, if you use caution.
By that I mean add teabags or loose tea gradually, until you have the desired effect.
Let me know the results, if you decide to try it.
I'm just guessing, but the nails may turn the soil acidic, while the teabags turn it alkaline.