Bottlebrush buckeye
Aesculus parviflora · Sapindaceae
A huge, mounding shrub covered in tall, white, candle-like flower spikes in midsummer, when few shrubs are in bloom. The big, hand-shaped leaves turn clear yellow in autumn.
- Size
- 10 ft tall, 13 ft wide
- Zones
- 5 to 8
- Light
- Part sun to shade
- Flowers
- Late June to late July
- Pets
- Toxic (moderate)
- Job in a bed
- Anchor
A bed built around bottlebrush buckeye
The planner designed this bed around bottlebrush buckeye when this page was made: a 30 × 14 ft (9.1 × 4.3 m) English border in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why bottlebrush buckeye stands where it does.
The plants
- 1 Bottlebrush buckeye × 1, white
- 2 Green-and-gold × 34, yellow
- 3 Jacob's ladder 'Stairway to Heaven' × 13, blue
- 4 Clumping bamboo 'Rufa' × 1, green leaves
- 5 Japanese anemone 'Honorine Jobert' × 5, white
- 6 Tall astilbe 'Superba' × 3, purple
- 7 Northern sea oats 'River Mist' × 8, green
- 8 Indian pink × 13, red
- 9 English primrose × 40, yellow
- 10 Sweet violet × 107, purple
- 11 Scarlet coral bells × 13, red
- 12 Canada lily × 5, orange
- 13 Snowdrop × 15, white
- 14 Yellow trout lily × 12, yellow
Why this plant
- The only bold leaves here. The rest are medium and fine. A change of leaf keeps plants distinct when nothing is in flower.
- The only spires. The others are daisies, bells, open bowls and others. Shape reads at a distance, where colours blur.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So do clumping bamboo 'Rufa' and northern sea oats 'River Mist'.
Why here
- Anchors a back corner. At 10 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 tall astilbe 'Superba' (4 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 June to late July.
- In company. With Indian pink, scarlet coral bells and Canada lily in late June: 4 kinds at once.
Planned as an English border: 30 of the 35 groups (86%) are drifts, longer along the bed than they are deep. Clumping bamboo 'Rufa' and northern sea oats 'River Mist' carry the bed through winter. Sweet violet is planted in 27 places along the bed, which gives it rhythm.
The planner's own design check: 12 Excellent, 4 Good, 1 Satisfactory.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where bottlebrush buckeye goes in a border
At 10 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.
One of the best native shrubs, for gardens with the room: it suckers into a mound wider than it is tall. Plant it where it can spread, and leave it unpruned.
- A magnificent specimen for a large, shady space
- Under tall trees
- Summer flowers in shade
What to plant with bottlebrush buckeye
Plants recorded as good partners for it, and what each pairing does:
- Hosta: its green leaves are a setting for the flowers, before and after; a low mound at the foot of its spires; low enough (18 in) to stand in front of it.
- Christmas fern: its dark green leaves are a setting for the flowers, before and after; medium leaves against its bold ones; low enough (20 in) to stand in front of it.
- Solomon's seal: flowers first, early May to late May, so the spot is never empty; medium leaves against its bold ones; low enough (3 ft) to stand in front of it.
Questions about bottlebrush buckeye
Does bottlebrush buckeye need sun or shade?
Bottlebrush buckeye grows in part sun (4 to 6 hours of sun, including some afternoon sun), part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light).
It wants soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.
What zones does bottlebrush buckeye grow in?
USDA zones 5 to 8. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does bottlebrush buckeye flower in my zone?
In zone 5 it flowers late June to late July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 5 | Late June to late July |
|---|---|
| Zone 6 | Late June to late July |
| Zone 7 | Late June to mid July |
| Zone 8 | Late 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 bottlebrush buckeye 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 13 ft (400 cm), so a group knits into one patch.
It grows 10 ft (300 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many bottlebrush buckeye 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 bottlebrush buckeye poisonous to dogs and cats?
Yes: moderate toxicity to people, dogs, cats and horses. All parts are poisonous if eaten. The seeds are the most poisonous part.
Rated from NC State Extension and the ASPCA. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like bottlebrush buckeye?
These come closest to doing what bottlebrush buckeye does, and no toxicity is recorded for them:
- Witch hazel 'Diane': the same job in a bed and the same size; flowers early February to mid March, red, not white.
- Red osier dogwood: the same job in a bed and the same colour; 20 in shorter, 3½ ft 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 bottlebrush buckeye?
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.
Will bottlebrush buckeye spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by suckers into a wider clump. Remove the outer shoots to contain it.
What flowers after bottlebrush buckeye?
Bottlebrush buckeye is over by late July. These start as it finishes and carry the same spot on, so it never goes flat:
- Panicle hydrangea 'Limelight': from mid July to early October, 7 ft tall, to stand in front of it and cover its fading stems.
- Tiger lily: from late July to late August, 4 ft tall, to stand in front of it and cover its fading stems.
- Garden phlox: from mid July to early September, 3½ ft tall, to stand in front of it and cover its fading stems.
What does bottlebrush buckeye look like in winter?
Bottlebrush buckeye drops its leaves and stands as bare branches. That is when to see its shape, and to prune it if it needs pruning.
Is bottlebrush buckeye good for bees and butterflies?
Bottlebrush buckeye is visited by pollinators, butterflies and hummingbirds.
It is native to the United States.
In these guides
- Garden plants toxic to cats
- Garden plants toxic to dogs
- Native plants for shade
- Plants for hummingbirds
- Plants for butterflies
- Plants with spires: vertical accents
- Plants for a white garden
Every fact on record
- Type
- Shrub
- Size
- 10 ft (300 cm) tall, 13 ft (400 cm) wide
- Plant
- 10 ft (300 cm) apart
- Height class
- Super tall (over 6½ ft)
- Place in the bed
- Back
- Flowers
- Late June to late July; upright spires; white
- Leaves
- Bold texture, deciduous; green
- Shape
- Rounded, spreading
- Hardy in
- USDA zones 5 to 8
- Light
- Part sun, part shade, shade
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Sapindaceae
- Comes from
- Al, GA, SC, FL
- Attracts
- Pollinators, butterflies, hummingbirds
Checked against NC State Extension and ASPCA poison lists. 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.