Seven-son flower
Heptacodium miconioides · Caprifoliaceae
Scented white flowers in late summer; then the calyces turn cherry red and look like a second flowering in October. The bark peels in pale, papery strips.
- Size
- 16½ ft tall, 11½ ft wide
- Zones
- 5 to 9
- Light
- Full sun to part sun
- Flowers
- Late August to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Anchor
A bed built around seven-son flower
The planner designed this bed around seven-son flower when this page was made: a 30 × 14 ft (9.1 × 4.3 m) English border in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why seven-son flower stands where it does.
The plants
- 1 Seven-son flower × 1, white
- 2 Bloody cranesbill 'Max Frei' × 17, pink
- 3 Creeping phlox 'Emerald Blue' × 8, blue
- 4 Dwarf Alberta spruce × 1, green leaves
- 5 Switchgrass 'Prairie Sky' × 3, tan
- 6 Sneezeweed × 4, yellow
- 7 White mugwort × 7, cream
- 8 Gloriosa daisy × 13, yellow
- 9 Purple milkweed × 8, purple
- 10 Orange New Zealand sedge × 5, bronze leaves
- 11 Coneflower 'Green Jewel' × 14, green
- 12 Winter heath × 22, pink
- 13 Black-eyed Susan × 3, yellow
- 14 Easter lily × 6, white
- 15 Allium 'Globemaster' × 6, purple
- 16 Henry's lily × 4, orange
Why this plant
- The only dense clusters. The others are open bowls, airy sprays, daisies and others. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 16½ ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to white mugwort (5 ft): 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 five weeks. From late August to mid September.
- Fills no gap. Every week it is in flower, at least five other kinds are too. It thickens a season that is already full.
Planned as an English border: 26 of the 27 groups (96%) are drifts, longer along the bed than they are deep. The back corners are held by seven-son flower and dwarf Alberta spruce, the tallest plants on the plan. The flowering is at its height in early August, with 8 kinds out together.
The planner's own design check: 12 Excellent, 4 Good, 1 Needs revision. Its weakest point is height and scale: Heights average about 14 in at the front, 3 ft in the middle and 5 ft at the back. Allium 'Globemaster' is airy enough to see through, so it comes forward of its height.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where seven-son flower goes in a border
At 16½ ft it belongs at the back of a bed. In the planner's ten height classes it is super tall (over 6½ ft).
Its job: anchor. A shrub that gives the bed permanent structure. Planted singly, as soon as the front edge is laid; everything else is arranged around it.
A large shrub or small tree with something to offer in every season, including winter. It flowers when little else does and is thick with late butterflies.
- Late flowers for butterflies
- Peeling winter bark
- A tall anchor for a large bed
What to plant with seven-son flower
Plants recorded as good partners for it, and what each pairing does:
- Switchgrass 'Northwind': in flower together for five weeks, from late August; fine leaves against its bold ones; low enough (5½ ft) to stand in front of it.
- Japanese anemone: in flower together for five weeks, from late August; medium leaves against its bold ones; low enough (3 ft) to stand in front of it.
- Sedum 'Autumn Joy': in flower together for five weeks, from late August; low enough (24 in) to stand in front of it.
Questions about seven-son flower
Does seven-son flower need sun or shade?
Seven-son flower grows in full sun (6 or more hours of direct sun a day) and part sun (4 to 6 hours of sun, including some afternoon sun).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells.
What zones does seven-son flower grow in?
USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does seven-son flower flower in my zone?
In zone 5 it flowers late August to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 5 | Late August to mid September |
|---|---|
| Zone 6 | Late August to mid September |
| Zone 7 | Mid August to mid September |
| Zone 8 | Mid August to mid September |
| Zone 9 | Early August to mid September |
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 seven-son flower be planted?
10 ft (300 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 11½ ft (350 cm), so a group knits into one patch.
It grows 16½ ft (500 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many seven-son flower plants do I need?
Usually one. At 10 ft (300 cm) across, it is a plant you place, not one you mass. For a hedge or screen, set them 10 ft apart: two plants for a 10 ft run.
In the bed above, the planner used one in one group.
Is seven-son flower 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.
Is there a native plant like seven-son flower?
Seven-son flower comes from China. These North American natives come closest to doing its job:
- Shadblow serviceberry: the same job in a bed, the same size and the same colour; flowers mid April to early May, medium leaves, not bold.
- Oakleaf hydrangea 'Alice': the same job in a bed and the same colour; 6½ ft shorter, 20 in narrower.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat seven-son flower?
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 seven-son flower?
Seven-son flower is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Common witch hazel: from mid October to late November, 15 ft tall.
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Swamp sunflower: from late September to late October, 6½ ft tall, to stand in front of it and cover its fading stems.
What does seven-son flower look like in winter?
Seven-son flower drops its leaves and stands as bare branches: it is grown for peeling winter bark. That is when to see its shape, and to prune it if it needs pruning.
Is seven-son flower good for bees and butterflies?
Seven-son flower is visited by butterflies and hummingbirds.
In these guides
- Pet-safe plants for a sunny border
- Plants for hummingbirds
- Plants for butterflies
- Plants that flower in fall
- Plants for a white garden
Every fact on record
- Type
- Shrub
- Size
- 16½ ft (500 cm) tall, 11½ ft (350 cm) wide
- Plant
- 10 ft (300 cm) apart
- Height class
- Super tall (over 6½ ft)
- Place in the bed
- Back
- Flowers
- Late August to mid September; dense clusters; white
- Leaves
- Bold texture, deciduous; dark green
- Shape
- Vase-shaped, clumping
- Hardy in
- USDA zones 5 to 9
- Light
- Full sun, part sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- None needed
- Family
- Caprifoliaceae
- Comes from
- China
- Attracts
- Butterflies, hummingbirds
- Stands up to
- 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.