Leadplant (Amorpha canescens) is a native wildflower at home in Wisconsin’s dry prairies and oak savannas, its silver-gray foliage and slender purple flower spikes offering both beauty and ecological depth. As a native legume, it plays a foundational role in prairie ecosystems by fixing nitrogen in the soil, enriching lean, sandy substrates, and supporting a wide array of pollinators and herbivores. Its deep, woody roots—sometimes reaching over ten feet—anchor soil and prevent erosion, making it especially valuable in restoration efforts on degraded slopes or drought-prone sites. Fire-adapted and long-lived, leadplant responds vigorously to prescribed burns, often increasing in abundance after fire. Its presence is a sign of a well-managed prairie, one that has escaped the pressures of overgrazing or prolonged neglect.
Ecologically, leadplant is generous. Its midsummer blooms attract a diversity of native pollinators, including solitary bees, bumblebees, and butterflies. The specialist bee Andrena quintilis relies heavily on leadplant for pollen. It also serves as a larval host for several butterfly caterpillars, such as the silver spotted skipper, gray hairstreak, and hoary edge, as well as some moth caterpillars, including the leadplant flower moth and the southern dogface sulfur. Its foliage feeds grasshoppers, beetles, and leafhoppers, and it is a favored browse for deer and rabbits, especially in its early years before stems become woody.
In cultivation, it prefers full sun and well-drained soils—sandy, gravelly, or loamy—and is highly drought-tolerant once established. Seeds require cold stratification or fall sowing to break dormancy, and germination is slow, often taking two to three years before flowering. Transplants or plugs can speed establishment, though young plants benefit from protection against browsing. Once mature, leadplant is low-maintenance and resilient, thriving in lean soils where other plants might falter. In a Wisconsin landscape, it pairs beautifully with other native species such as little bluestem (Schizachyrium scoparium), prairie dropseed (Sporobolus heterolepis), side-oats grama (Bouteloua curtipendula), prairie blazing star (Liatris pycnostachya), purple prairie clover (Dalea purpurea), wild quinine (Parthenium integrifolium), and switchgrass (Panicum virgatum). These companions not only complement leadplant’s form and bloom time but also reinforce the ecological integrity of a native planting.
(July)