In message , Chris Hogg
writes
On 27 Mar 2007 09:25:45 -0700, "Snowflake"
wrote:

I have been given a present of a blue hydrangea because I do not like
pink and the donor says there is a way to keep it blue but cannot
remember how. Any help is appreciated and the plant is to survive in
North of Scotland.
Ailsa

You need an acid soil. I don't know the geology of your part of the
world in detail, but I don't recall much chalk or limestone up there.
Most of northern Scotland is pre-Cambrian. Do your neighbours grow
rhododendrons or azaleas? If so, your soil is probably OK anyway.

Much of northern Scotland has acidic soil, if not from the underlying
rock, then from the till and peat. However there is, for example, the
outcrop of the Durness Limestone, and there are other calcareous rocks
(IIRC, a calcarous sandstone, contemporaneous with the chalk of England
underlies the Tertiary Volcanics of Skye.) Other younger rocks are the
Devonian Old Red Sandstones that underlie much of lowland northern
Scotland.
--
Stewart Robert Hinsley