Lead Plant
Amorpha canescens
Family: Fabaceae or Leguminosae
What it is like
Amorpha canescens is a deciduous Shrub growing to 1.2 m (4ft) by 1.5 m (5ft in). See above for USDA hardiness. It is hardy to UK zone 2. It is in flower from July to September. The species is hermaphrodite (has both male and female organs). It can fix Nitrogen. Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.
Height (m): 1.2
Where it is found
Dry sandy prairies, hills and woodland.
Eastern N. America - Indiana to Minnesota and Manitoba, south to Kansas and New Mexico.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 2
An infusion of the dried leaves makes a pleasant tasting yellow-coloured tea.
Oil: Oil
Tea: the various herb teas that can be used in place of tea, plus the genuine article.
Medicine
Rating: 2
An infusion of the leaves has been used to kill pinworms or any intestinal worms. The infusion is also used to treat eczema, the report does not say it if is used internally or externally. The dried and powdered leaves are applied as a salve to cuts and open wounds. A decoction of the root is used to treat stomach pains. A moxa of the twigs has been used in the treatment of neuralgia and rheumatism.
Anthelmintic: Expels parasites from the gut.
Eczema: Used in the treatment of eczema - a chronic health condition that affects the skin, causing redness, dryness, itching and infections.
Miscellany: Various medicinal actions that need more clarification.
Salve: Soothes and heals damaged skin.
Skin: Plants used in miscellaneous treatments for the skin.
Stomachic: Aids and improves the action of the stomach.
Other
Rating: 3
Plants have an extensive root system, they tolerate poor dry soils and are also wind resistant, they are used as a windbreak and also to prevent soil erosion. Resinous pustules on the plant contain 'amorpha', a contact and stomachic insecticide that also acts as an insect repellent.
Insecticide: Kills insects.
Miscellany: A rag-bag of items that are difficult to categorise.
Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Shelterbelt: Wind resistant plants than can be grown to provide shelter in the garden etc.
Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
Prefers a light well-drained sandy soil in sun or light shade. Tolerant of poor dry soils, plants can be invasive in rich soils. Wind resistant. A very hardy plant, tolerating temperatures down to about -25c but it frequently dies down to ground level in the winter, resprouting from the base in the following spring. A very ornamental plant. A deep rooted plant, it thrives best in hot, droughty seasons. It only ripens its seed in fine autumns. Immune to insect pests, the plant contains its own insecticide. At one time this plant was supposed to indicate the presence of lead in the soil. There is some confusion over the correct author of the Latin name of this plant. It is probably Pursh. as stated on the top of this sheet, but some books cite Nutt. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. The plant is heat tolerant in zones 8 through 1. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is multistemmed with multiple stems from the crown. The root pattern is a tap root similar to a carrot going directly down. The root pattern is suckering with new plants from underground runners away from the plant.
Propagating it: Seed - presoak for 12 hours in warm water and sow early spring in a greenhouse. The seed usually germinates in 1 - 2 months at 20°c. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts. Cuttings of half-ripe wood, June/July in a frame. High percentage. Cuttings of mature wood of the current seasons growth, autumn, in a sheltered position outdoors. Takes 12 months. Suckers in spring just before new growth begins. Layering in spring .
Best place to grow: Woodland Garden Sunny Edge; Cultivated Beds;
Habit: Shrub
Hardiness: 2-9
Growth:
Soil: Light (sandy), medium
Shade: Semi-shade, no shade
Moisture: Dry, moist