Blue Spruce Stonecrop Sedum is a vibrant, evergreen carpet of steel-blue, needle-like foliage that looks like a miniature forest of blue spruce trees hugging the ground. In early to mid-summer, bright yellow star-shaped flowers pop up on short stems, turning the whole mat into a cheerful pollinator hotspot. The contrast between the cool blue foliage and sunny yellow blooms is absolutely striking. It keeps looking sharp through fall and winter as a semi-evergreen mat.