Leadplant (Amorpha canescens) is a perennial woody shrub that attracts bees and butterflies and will grow from 2 to 3 feet tall. It blooms in summer with iridescent purple flowers that grow along a spiked flower stem. Delicate foliage is silver gray making an interesting backdrop to the blossoms. Thrives in full sun or partial shade in sandy or loamy soil.
I. Appearance and Characteristics
Amorpha canescens, known as leadplant, downy indigo bush, prairie shoestring, or buffalo bellows, is a small, perennial semi-shrub in the pea family (Fabaceae). This plant can be found growing in well-drained soils of prairies, bluffs, and open woodlands.
Amorpha canescens can be found in many locations throughout North America, ranging from southern parts of Canada south to Texas and New Mexico and spanning west to Montana and east to Michigan. Leadplant is typically found in dry prairie and savanna communities Leadplant prefers drier, well-drained soil of many different textures including sandy, gravely, and rocky soils. Finding leadplant indicates minimal livestock grazing and well-kept land that is not overgrown or that has experienced regular fire.
Amorpha canescens was described by Frederick Pursh in 1814. It falls under subfamily Papilionoideae of the family Fabaceae. The specific epithet “canescens” is a botanical Latin term meaning “becoming grey”. There have been further delineation beyond species of Amorpha canescens into distinct variants (such as the A. canescens var. glabrata) based on the amount of hairs and color of the leaves, however this further distinction is not typically accepted due to the wide variation in pubescence of the plant.
Typically between 0.3–1 m (1 ft 0 in – 3 ft 3 in) tall, leadplant can be identified by its small purple flowers grouped in long spikes and its grey-green leaflets that are alternate and pinnately compound. The plant produces fruits in the form of hairy legumes each with one seed inside. The flower and leafing pattern is similar to Amorpha fruticosa, however, A. canescens typically only grows to be 1 meter (3 ft 3 in) high and prefers drier habitats whereas A. fruticosa can grow to be 5 or 6 meters (16 or 20 ft) high and lives in wetter areas.
Depending on location, the flowers bloom from late June through mid-September.
II. How to Grow and Care
Sunlight and Soil
It thrives in full sun on average, dry to medium moisture, well-drained soils. Dry soil and drought tolerance.
Watering
Adapted to its native prairie habitat, leadplant thrives in conditions where moisture is infrequent yet the soil retains water well. This species exhibits a strong drought tolerance and prefers a balance between dryness and moderate humidity. Accordingly, it requires watering once every two weeks to maintain its vigor. Given that leadplant is more commonly grown outdoors, it’s important to consider that as an herbaceous perennial, the plant’s water needs will fluctuate with seasonal changes, especially during its active growth period in warmer months.
Fertilizing
For leadplant, fertilization boosts growth and flowering. Use balanced nutrition fertilizers annually, in early spring. Apply according to package directions, avoiding over-fertilization which can harm leadplant’s natural hardiness. Adjust application rate for plant size, reducing for younger plants. Always water thoroughly post-fertilization to aid nutrient absorption and prevent root burn. Experienced gardeners can tailor applications considering soil fertility, while beginners should follow standard guidelines for simplicity.
Pruning
Leadplant does not need pruning to maintain shape and promote vigorous growth.
Propagation
Leadplant thrives best when its seeds are sown directly in well-draining soil. Prior to planting, scarifying the seeds by lightly abrading the seed coat enhances germination rates. After scarification, sowing seeds in a sunny location and providing consistent moisture contributes to the successful propagation of leadplant. While the growth is gradual in the first few years, leadplant becomes a hardy, long-lived addition to any native garden, its deep roots making it especially drought-resistant over time.
Transplanting
Leadplant reaches peak transplant success in early spring to early summer (S2-S3), as these seasons provide ideal growing conditions. Choose a sunny location with well-draining soil to encourage a healthy transplant. Be gentle to avoid root damage during transplantation, which is vital for this perennial plant.
Pests and Diseases
No serious pest or disease issues. Keep an eye out for leaf spots, rust, powdery mildew or canker.
III. Uses and Benefits
Leadplant reaches peak transplant success in early spring to early summer (S2-S3), as these seasons provide ideal growing conditions. Choose a sunny location with well-draining soil to encourage a healthy transplant. Be gentle to avoid root damage during transplantation, which is vital for this perennial plant.