Purple sage care

Hi all

So when we originally planted the borders we put in some purple sage - I had a hell of a job to keep it alive and part of it shrivelled and died off (managed to save half) then last year virtually the same thing happened to the rest.

I've bought a new plant with fresh resolve and been watering it daily since I planted it about 3/4 weeks ago.

I'm looking at it and the bottom leaves are yellowing and I'm worried I'm about to start killing this one too!

How am I supposed to care for this plant in terms of watering etc