Bluestar 'Blue Ice'
Amsonia 'Blue Ice' ·
A compact bluestar with darker, lavender-blue flowers than the species, over a low mound that turns yellow in autumn.
- Size
- 18 in tall, 24 in wide
- Zones
- 4 to 9
- Light
- Full sun to part sun
- Flowers
- Mid May to late June
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around bluestar 'Blue Ice'
The planner designed this bed around bluestar 'Blue Ice' 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 bluestar 'Blue Ice' stands where it does.
The plants
- 1 Bluestar 'Blue Ice' × 3, blue
- 2 Winter heath × 8, pink
- 3 Sea thrift × 8, white
- 4 False sunflower 'Summer Sun' × 3, yellow
- 5 Brown-eyed Susan × 5, yellow
- 6 Eastern prickly pear × 1, yellow
- 7 Camassia × 4, blue
- 8 Red spider lily × 7, red
Why this plant
- The only dense clusters. The others are bells, globes, daisies and others. Shape reads at a distance, where colours blur.
Why here
- In the middle. At 18 in it is seen over eastern prickly pear (10 in) in front of it.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for six weeks. From mid May to late June.
- Part of the bed's peak. With sea thrift and camassia in mid May: 3 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. The bed is balanced: the left half carries 53% of the visual weight and the right half 47%. Low plants run along 97% of the front edge: eastern prickly pear, sea thrift and winter heath.
The planner's own design check: 10 Excellent, 7 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 bluestar 'Blue Ice' goes in a border
At 18 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
Small enough for the front of a bed, where the species is too big. Plant in threes for a low band of blue in May and yellow in October.
- Front-of-border blue in late spring
- Edging
- Small gardens
What to plant with bluestar 'Blue Ice'
Plants recorded as good partners for it, and what each pairing does:
- Cranesbill 'Rozanne': in flower together for three weeks, from early June.
- Salvia 'May Night': in flower together for four weeks, from late May; spires rising out of its mound.
- Coral bells: its burgundy leaves are a setting for the flowers, before and after.
Questions about bluestar 'Blue Ice'
Does bluestar 'Blue Ice' need sun or shade?
Bluestar 'Blue Ice' 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 bluestar 'Blue Ice' grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does bluestar 'Blue Ice' flower in my zone?
In zone 5 it flowers mid May to late June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 4 | Late May to late June |
|---|---|
| Zone 5 | Mid May to late June |
| Zone 6 | Early May to late June |
| Zone 7 | Early May to mid June |
| Zone 8 | Late April to mid June |
| Zone 9 | Mid April to early June |
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 bluestar 'Blue Ice' be planted?
18 in (45 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 18 in (45 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many bluestar 'Blue Ice' 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 bluestar 'Blue Ice' poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension. Not considered poisonous, but the milky sap can irritate sensitive skin.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like bluestar 'Blue Ice'?
Bluestar 'Blue Ice' is not native to North America. These North American natives come closest to doing its job:
- Stokes' aster: the same job in a bed, the same size and the same colour; flowers late June to mid August.
- Eastern bee balm: the same job in a bed, the same size and the same flowering time; belongs in the middle, not at the front, pink, not blue.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after bluestar 'Blue Ice'?
Bluestar 'Blue Ice' is over by late June. These start as it finishes and carry the same spot on, so it never goes flat:
- Black-eyed Susan: from mid July to mid September, 24 in tall.
- Butterfly weed: from late June to early August, 24 in tall.
- Yarrow: from mid June to late August, 24 in tall.
What does bluestar 'Blue Ice' look like in winter?
Bluestar 'Blue Ice' 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 Amsonia
- Arkansas bluestar Amsonia hubrichtii
- Bluestar Amsonia tabernaemontana
- Bluestar 'Storm Cloud' Amsonia tabernaemontana 'Storm Cloud'
In these guides
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 18 in (45 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Mid May to late June; dense clusters; blue
- Leaves
- Medium texture, herbaceous; dark green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun, part sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- Light, in spring
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.