Top Plants That Thrive in Clay. Golden black-eyed Susan is a summer staple for sunny borders. 'Goldsturm' is the most commonly grown variety. It spreads quickly, but not invasively, to fill a planting bed with long-lasting color.
Thalictrum delavayi 'Album', also can come in lilac/ purple tones, a great binder for the border as the airy clouds of flowers blend and create unity. Likes semi shade so will cope with the Hebe and Fir tree.