Most plants have quite broad variation in what they'll tolerate, so you really only need a rough value @Winston_The_Gravity_Man . The red cabbage thing is interesting - not heard of that before.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
What I do know is that the "juice" from red cabbage left on a chopping board turns dark blue-black as soon as our tap water touches it. Hard water, alkaline (but I don't really need to know how alkaline).
Doncaster, South Yorkshire. Soil type: sandy, well-drained
Posts
The red cabbage thing is interesting - not heard of that before.
I live in west central Scotland - not where that photo is...
A quick google got this:
Red Cabbage pH Indicator Colors
The coloured chemiclas are anthocyanins, so red wine would work. But I can think of better things to do with it.
"Have nothing in your garden that you don't know to be useful, or believe to be beautiful."