I am often asked to recommend plants for problematic garden areas during my call-in radio program or after public-speaking engagements. As a result, over the years I have developed a list of my top picks for sunny and shady gardens depending on whether the soil is dense, heavy, and clay-based, or lean, sandy, and quick-draining. Fortunately, I have experience gardening with both soil types, and so I know that each presents its own challenges and opportunities. Here are a few options for perennials, trees, and shrubs that can survive and even thrive in the trickiest soil conditions.