Shrubs for heavy clay soil
I have an area of lawn that I'm planning to develop into a garden, but with more shrubs, small trees, and native plants, rather than a perennial flower garden.
I'd like some ideas what will grow in heavy clay soil, , with one edge close to the canopy (is that the right word?) of a Black Walnut tree. I am willing to amend the soil somewhat, but I won't go overboard, trying to plant something exotic. So far what works there are Redbud trees, a Syringa vulgares, and a snowball Viburnum. I lost a Kerria japonica, rugosa roses, and crabapple trees.