What to do with hardcore?

[Bolshybookworm]

We have a wide path down the side of our house that I would like to narrow and make 2 borders flanking it (it's pretty unattractive at the moment). It's pebbles with sand and loose hardcore underneath (not sure how deep). If I dug out the pebbles, would I be able to mix in some topsoil and plant in the hardcore? Or do I need to dig it all up (bleuch)?

I was thinking of using plants that like free draining soil- herbs, penstemons, echinacea, rudbeckia, grasses etc (which I can't use in the rest of my garden as it's heavy clay).

Yep, dig it up until you get to soil. Then put a good soil mix with compost, soil wetters and mulch.

We did this to make border next to our driveway. It is avery well-made drive, as we discovered, and needed much work with a jackhammer.

Don't cut corners here, because you won't want to do it again if the flowers go bleurgh the first time.

Oh joy. The last owners were pretty shoddy when it comes to DIY, so hopefully it won't be too hard to dig up (seems pretty loose under the pebbles). At least it will give me a chance to have one corner of the garden that isn't solid, soggy clay.