Astilbe
Astilbe x arendsii · Saxifragaceae Popular
Feathery plumes of flowers rise above fern-like leaves, brightening shady, moist spots in early summer. The dried plumes can be left standing for winter interest.
- Size
- 24 in tall, 18 in wide
- Zones
- 4 to 8
- Light
- Part shade to shade
- Flowers
- Late June to mid July
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around astilbe
The planner designed this bed around astilbe when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why astilbe stands where it does.
The plants
- 1 Astilbe × 3, pink
- 2 Lingonberry × 8, pink
- 3 Lungwort 'Raspberry Splash' × 5, pink
- 4 Silvery glade fern × 3, green leaves
- 5 Bicolor monkshood × 3, blue
- 6 Bleeding heart × 1, white
- 7 Hardy cyclamen × 12, pink
- 8 Giant snowdrop × 5, white
Why this plant
- A classic partner for bicolor monkshood and bleeding heart. All are on this plan. A pairing gardeners have proved outranks a general rule.
- The only plumes. The others are bells, dense clusters and spires. Shape reads at a distance, where colours blur.
Why here
- At the back. At 24 in it is seen over lungwort 'Raspberry Splash' (12 in) in front of it, and has nothing behind it to hide.
- A step in the back row. Next to silvery glade fern (3 ft) and bleeding heart (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for five weeks. From late June to mid July.
- Fills a gap. For three of those weeks nothing else on the plan is in flower.
Planned as an English border: 5 of the 5 groups (100%) are drifts, longer along the bed than they are deep. A cool scheme: pink, blue and white. Pink runs through the planting: 4 of the 7 kinds grown for their flowers have it.
The planner's own design check: 11 Excellent, 5 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 astilbe goes in a border
At 24 in it belongs in the middle of a bed. In the planner's ten height classes it is medium short (18 to 24 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
Feathery plumes and ferny leaves are the classic contrast to the broad leaves of hosta. It must not dry out: brown, crisp leaf edges mean the soil is too dry. Leave the seed heads standing for winter.
- Colour in damp shade
- Feathery texture against bold hosta leaves
- Beside water
What to plant with astilbe
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; bold leaves against its fine ones; happy in the same moist soil.
- Japanese painted fern: its silver leaves are a setting for the flowers, before and after; happy in the same moist soil.
- Bleeding heart: flowers first, early May to early June, so the spot is never empty; happy in the same moist soil.
Choosing between it and a look-alike? Astilbe vs Goat's beard.
Questions about astilbe
Does astilbe need sun or shade?
Astilbe grows in 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 plenty of water.
What zones does astilbe grow in?
USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °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 astilbe flower in my zone?
In zone 5 it flowers late June to mid July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Late June to late July |
|---|---|
| Zone 5 | Late June to mid July |
| Zone 6 | Late June to mid July |
| Zone 7 | Mid June to mid July |
| Zone 8 | 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 astilbe be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 24 in (60 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many astilbe plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 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 three in one group.
Is astilbe 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.
What flowers after astilbe?
Astilbe is over by mid July. 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.
- Japanese anemone: from mid August to early October, 3 ft tall.
- Hosta 'Guacamole': from early August to late August, 24 in tall.
What does astilbe look like in winter?
Astilbe dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
More Astilbe
- Astilbe 'Bridal Veil' Astilbe x arendsii 'Bridal Veil'
- Astilbe 'Chocolate Shogun' Astilbe 'Chocolate Shogun'
- Astilbe 'Deutschland' Astilbe japonica 'Deutschland'
- Astilbe 'Fanal' Astilbe x arendsii 'Fanal'
- Astilbe 'Ostrich Plume' Astilbe thunbergii 'Straussenfeder'
- Astilbe 'Purple Candles' Astilbe chinensis 'Purpurkerze'
- Astilbe 'Sprite' Astilbe simplicifolia 'Sprite'
- Chinese astilbe 'Visions' Astilbe chinensis 'Visions'
- Dwarf Chinese astilbe Astilbe chinensis 'Pumila'
- Tall astilbe 'Superba' Astilbe chinensis var. taquetii 'Superba'
In these guides
Every fact on record
- Type
- Perennial
- Size
- 24 in (60 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Medium short (18 to 24 in)
- Place in the bed
- Middle
- Flowers
- Late June to mid July; feathery plumes; pink, red, white
- Leaves
- Fine texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 4 to 8
- Light
- Part shade, shade
- Soil
- Rich, evenly moist
- Water
- High
- Feeding
- Moderate, in spring
- Family
- Saxifragaceae
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.