Well, I just think you have to grow some “Yerba Buena.” CLAY, SAND & SHADE TOLERANT, it also grows under oaks & makes a lush, flat, evergreen groundcover for shade, spreading to 6’ across & up to 2’ tall. Fantastic used as a trailer, especially over a shady wall, you can even grow it in a hanging basket. It roots along the stems, not by rhizomes & is not invasive. The rich, green, scalloped leaves are held oppositely on the stems & little, flaring, tubular, white to purple flowers appear Summer thru Fall. Easy, tough & long lived, it smells heavenly & makes a healthful & tasty, mint-like tea. Used medicinally by native people for indigestion, insomnia, fevers, colds, arthritic pain & toothaches. Very pretty & deer resistant, too! It’s perfect in every way! Just give an annual bit of compost & cut back occasionally to promote bushiness. Drought tolerant, but best with some Summer water.