"scfundogs" writes:
I have a Nikko hydrangea, planted a couple of months ago, that has grown
quite a bit and looks very healthy. I purchased it from a nursery with one
mophead already on it but it was still green. The mophead has also grown
but hasn't colored at all.

The colour of the blooms is determined by the soil's pH or something,
and you can swap over their colour by adding the appropriate mineral to
the soil. The actual brilliance of the colour is determined largely by
the hydrangea's genes I guess.

So I'm wondering whether your new acquisition is planted in soil that
is different from what the others are growing in? Maybe there is a lot
of lime or cement waste or something in its soil? You haven't mentioned
adding blueing (or pinking) compound to its soil, have you tried that?
I think any mushroom compost added to the soil would have made it a bit
acid.
--
John Savage (my news address is not valid for email)