Leadplant
Amorpha canescens · Fabaceae
A small prairie shrub with silver-grey, ferny leaves and spikes of tiny purple flowers with bright orange anthers in midsummer. Its roots go down four metres.
- Size
- 2½ ft tall, 2½ ft wide
- Zones
- 2 to 9
- Light
- Full sun
- Flowers
- Late June to early August
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around leadplant
The planner designed this bed around leadplant when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why leadplant stands where it does.
The plants
- 1 Leadplant × 1, purple
- 2 Seaside daisy × 10, lavender
- 3 Sea thrift × 8, pink
- 4 Stiff goldenrod × 3, yellow
- 5 Little bluestem × 3, blue-green leaves
- 6 Wild lupine × 8, blue
- 7 Schubert's allium × 2, pink
- 8 Grecian windflower × 12, white
Why this plant
- A classic partner for little bluestem. Both are on this plan. A pairing gardeners have proved outranks a general rule.
- The only purple.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does little bluestem.
Why here
- At the back. At 2½ ft it is seen over seaside daisy (10 in) in front of it, and has nothing behind it to hide.
- A step in the back row. Next to stiff goldenrod (4 ft) and wild lupine (20 in): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A shrub is seen as an object, and needs clear ground around it.
Why now
- In flower for six weeks. From late June to early August.
- In company. With seaside daisy in late June: 2 kinds at once.
Planned as an English border: 6 of the 7 groups (86%) are drifts, longer along the bed than they are deep. Cool colours (purple, lavender, pink and blue) with yellow as the warm note, and white to calm things between them. Low plants run along 99% of the front edge: sea thrift and seaside daisy.
The planner's own design check: 13 Excellent, 4 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where leadplant goes in a border
At 2½ ft it belongs in the middle of a bed. In the planner's ten height classes it is medium (24 in to 2½ ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
Use it as you would a perennial, among prairie grasses and flowers. It is slow to start and then lives for decades through any drought. Rabbits and deer love it when young.
- Dry prairie and gravel gardens
- Silver foliage among grasses
- Native bees
What to plant with leadplant
Plants recorded as good partners for it, and what each pairing does:
- Butterfly weed: purple against orange, opposite each other on the colour wheel, in flower together for six weeks; happy in the same dry soil.
- Little bluestem: its blue-green leaves are a setting for the flowers, before and after; happy in the same dry soil.
- Purple coneflower: in flower together for six weeks, from late June.
Questions about leadplant
Does leadplant need sun or shade?
Leadplant grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does leadplant grow in?
USDA zones 2 to 9. It is hardy to zone 2, which means it survives winter nights down to about −40 °F (−40 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does leadplant flower in my zone?
In zone 5 it flowers late June to early August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Early July to early August |
|---|---|
| Zone 4 | Early July to early August |
| Zone 5 | Late June to early August |
| Zone 6 | Late June to early August |
| Zone 7 | Late June to late July |
| Zone 8 | Late June to late July |
| Zone 9 | Mid June to mid July |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should leadplant be planted?
24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 2½ ft (75 cm), so a group knits into one patch.
It grows 2½ ft (75 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many leadplant plants do I need?
At 24 in apart, set out in staggered rows:
- 3 to fill 10 square feet (about 1 m²)
- 6 for a single row 10 ft (3 m) long
- 10 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used one in one group.
Is leadplant poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat leadplant?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
What flowers after leadplant?
Leadplant is over by early August. These start as it finishes and carry the same spot on, so it never goes flat:
- Lilyturf: from early August to mid September, 16 in tall, to stand in front of it and cover its fading stems.
- Sedum 'Autumn Joy': from mid August to mid October, 24 in tall.
- Black-eyed Susan 'Goldsturm': from late July to late September, 2 ft tall.
What does leadplant look like in winter?
Leadplant drops its leaves and stands as bare branches. That is when to see its shape, and to prune it if it needs pruning.
Is leadplant good for bees and butterflies?
Leadplant is visited by pollinators, bees, specialist bees, butterflies, moths and songbirds.
It is native to the United States and Canada.
In these guides
- Pet-safe plants for a sunny border
- Garden plants native to Canada
- Plants for butterflies
- Plants for bees
- Plants that feed garden birds
- Shrubs under 4 feet for small gardens
- Plants with spires: vertical accents
- Silver and grey-leaved plants
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Shrub
- Size
- 2½ ft (75 cm) tall, 2½ ft (75 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Medium (24 in to 2½ ft)
- Place in the bed
- Middle
- Flowers
- Late June to early August; upright spires; purple
- Leaves
- Fine texture, deciduous; grey-green
- Shape
- Rounded, clumping
- Hardy in
- USDA zones 2 to 9
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Fabaceae
- Comes from
- North America
- Attracts
- Pollinators, bees, specialist bees, butterflies, moths, songbirds
- Stands up to
- Drought, poor soil
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.