I live on the North Downs which of course produces an alkaline soil.
But, I want to fill a new bed I've dug with ericaceous and gritty soil to grow some alpines.
I can buy bags of ericaceous soil, and mix inert grit with it, but will this be the best way to go about it, or is there a better recipe?
Also, how deep should I dig, and should I line the hole with something to contain the roots in the acid soil?
To start the ball rolling:
No experience of this, but some thoughts anyway
I'd fill the bed to twice the depth that you think the roots will grow but not line the hole as I don't think the roots will come to harm if they meet alkaline soil, just not grow well into it. The soil you put in will settle over time so start with the bed higher than you want it, and top dress with more soil when it starts to get low, or perhaps a little every year.
I know nothing about the "mix" but remember that alpines like free draining soil so adding the grit is a good idea, how about lining the bottom of the bed with a layer of grit, or gravel, too?
Just had a google and came up with these:
Don't see ericaceous soil mentioned!