Swamp milkweed 'Ice Ballet'
Asclepias incarnata 'Ice Ballet' · Apocynaceae
A white-flowered swamp milkweed: flat clusters of pure white, vanilla-scented flowers on upright stems, followed by slender pods of silky seed.
- Size
- 3½ ft tall, 24 in wide
- Zones
- 3 to 9
- Light
- Full sun to part sun
- Flowers
- Early July to mid August
- Pets
- Toxic (moderate)
- Job in a bed
- Drift
A bed built around swamp milkweed 'Ice Ballet'
The planner designed this bed around swamp milkweed 'Ice Ballet' 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 966 that suit those conditions, and says below why swamp milkweed 'Ice Ballet' stands where it does.
The plants
- 1 Swamp milkweed 'Ice Ballet' × 3, white
- 2 Winter heath × 7, pink
- 3 Coral bells 'Firefly' × 8, red
- 4 Gloriosa daisy 'Indian Summer' × 8, yellow
- 5 Silver sage × 1, silver leaves
- 6 Sunset hyssop × 3, orange
- 7 Camassia × 3, blue
- 8 Surprise lily × 7, pink
Why this plant
- The only flat plates. The others are bells, airy sprays, daisies and others. Shape reads at a distance, where colours blur.
- The only white. White sits between stronger colours and calms them.
Why here
- Anchors a back corner. At 3½ 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 gloriosa daisy 'Indian Summer' (3 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 7 weeks. From early July to mid August.
- Part of the bed's peak. With coral bells 'Firefly', gloriosa daisy 'Indian Summer' and sunset hyssop in mid July: 4 kinds at once. No week has more.
Planned as an English border: 7 of the 7 groups (100%) are drifts, longer along the bed than they are deep. Hot and cool in equal measure: red, yellow and orange against pink and blue, with white to calm things between them. The most in flower at one time is 4 kinds, from mid July.
The planner's own design check: 13 Excellent, 3 Good, 1 Satisfactory. 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 swamp milkweed 'Ice Ballet' goes in a border
At 3½ ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
It stays in a clump, unlike common milkweed, and feeds monarch caterpillars just as well. The white cools a border of pinks and purples, and lasts a week in a vase.
- Monarch gardens in a small space
- Rain gardens and damp soil
- White borders
What to plant with swamp milkweed 'Ice Ballet'
Plants recorded as good partners for it, and what each pairing does:
- Joe Pye weed 'Little Joe': in flower together for four weeks, from late July; bold leaves against its medium ones; happy in the same moist soil.
- Blue flag iris: flowers first, late May to late June, so the spot is never empty.
- Cardinal flower: in flower together for four weeks, from late July.
Questions about swamp milkweed 'Ice Ballet'
Does swamp milkweed 'Ice Ballet' need sun or shade?
Swamp milkweed 'Ice Ballet' 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 soil that stays evenly moist, of average fertility, and a good soak in dry spells. It copes with soil that stays wet.
What zones does swamp milkweed 'Ice Ballet' grow in?
USDA zones 3 to 9. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does swamp milkweed 'Ice Ballet' flower in my zone?
In zone 5 it flowers early July to mid August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Mid July to late August |
|---|---|
| Zone 4 | Mid July to late August |
| Zone 5 | Early July to mid August |
| Zone 6 | Early July to mid August |
| Zone 7 | Late June to early August |
| Zone 8 | Late June to early August |
| Zone 9 | Late June to early August |
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 swamp milkweed 'Ice Ballet' be planted?
20 in (50 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 3½ ft (110 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many swamp milkweed 'Ice Ballet' plants do I need?
At 20 in apart, set out in staggered rows:
- 4 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 14 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 swamp milkweed 'Ice Ballet' poisonous to dogs and cats?
Yes: moderate toxicity to people, dogs, cats and horses. All parts are poisonous if eaten. The sap can irritate skin and eyes.
Rated from NC State Extension and the ASPCA. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like swamp milkweed 'Ice Ballet'?
These come closest to doing what swamp milkweed 'Ice Ballet' does, and no toxicity is recorded for them:
- Garden phlox 'David': the same job in a bed, the same size and the same colour; flowers mid July to early September.
- Bee balm 'Jacob Cline': the same job in a bed and the same flowering time; 4 in wider, red, not white.
- Wild quinine: the same job in a bed, the same size, the same flowering time and the same colour; bold leaves, not medium, wants average soil.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat swamp milkweed 'Ice Ballet'?
Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after swamp milkweed 'Ice Ballet'?
Swamp milkweed 'Ice Ballet' is over by mid August. These start as it finishes and carry the same spot on, so it never goes flat:
- Japanese anemone: from mid August to early October, 3 ft tall.
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Lilyturf: from early August to mid September, 16 in tall, to stand in front of it and cover its fading stems.
What does swamp milkweed 'Ice Ballet' look like in winter?
Swamp milkweed 'Ice Ballet' 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.
Is swamp milkweed 'Ice Ballet' good for bees and butterflies?
Swamp milkweed 'Ice Ballet' is visited by pollinators, butterflies and beneficial insects.
It is a host plant: the caterpillars of monarch (at risk) feed on its leaves. A butterfly can only lay its eggs on its host plants, so these do more for it than any nectar flower.
It is native to the United States (this is a named variety of the native plant).
More Asclepias
- Butterfly weed Asclepias tuberosa
- Common milkweed Asclepias syriaca
- Purple milkweed Asclepias purpurascens
- Showy milkweed Asclepias speciosa
- Swamp milkweed Asclepias incarnata
- Whorled milkweed Asclepias verticillata
In these guides
- Plants for wet soil and rain gardens
- Deer-resistant perennials for full sun
- Rabbit-resistant plants
- Garden plants toxic to cats
- Garden plants toxic to dogs
- Native perennials for pollinators
- Plants for butterflies
- Plants for a white garden
- Host plants for the monarch
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 3½ ft (110 cm) tall, 24 in (60 cm) wide
- Plant
- 20 in (50 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- Early July to mid August; flat plates; white
- Leaves
- Medium texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 9
- Light
- Full sun, part sun
- Soil
- Average, evenly moist
- Water
- Moderate
- Feeding
- None needed
- Family
- Apocynaceae
- Comes from
- Central & E. Canada to W. Central & E. U.S.A
- Attracts
- Pollinators, butterflies, beneficial insects
- Host plant for
- Monarch (at risk)
- Stands up to
- Deer, rabbits, wet soil
Checked against NC State Extension, ASPCA poison lists and VASCAN (plants of Canada). 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.