Balloon flower 'Sentimental Blue'
Platycodon grandiflorus 'Sentimental Blue' · Campanulaceae
A dwarf balloon flower: puffed buds like small balloons open to wide, violet-blue stars on a plant a hand's width high.
- Size
- 8 in tall, 12 in wide
- Zones
- 3 to 8
- Light
- Full sun to part sun
- Flowers
- Early July to late August
- Pets
- No toxicity recorded
- Job in a bed
- Edging
A bed built around balloon flower 'Sentimental Blue'
The planner designed this bed around balloon flower 'Sentimental Blue' 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 balloon flower 'Sentimental Blue' stands where it does.
The plants
- 1 Balloon flower 'Sentimental Blue' × 8, blue
- 2 Winter heath × 4, pink
- 3 Little bluestem 'The Blues' × 3, tan
- 4 Tatarian aster 'Jindai' × 4, purple
- 5 Silver sage × 1, silver leaves
- 6 Butterfly weed × 3, orange
- 7 Hardy gladiolus × 4, pink
- 8 Tulip × 12, red
Why this plant
- The only blue.
Why here
- On the front edge. At 8 in it frames the bed without hiding it, and it is in leaf all season. It finishes 36% of the edge.
- 8 plants in 2 runs (5 and 3). Runs of different lengths make the edge a frame, not a ruled line.
Why now
- In flower for 8 weeks. From early July to late August.
- Part of the bed's peak. With little bluestem 'The Blues' and butterfly weed in early August: 3 kinds at once. No week has more.
Planned as an English border: 6 of the 6 groups (100%) are drifts, longer along the bed than they are deep. Winter heath flowers longest, for 13 weeks. Tatarian aster 'Jindai' and little bluestem 'The Blues' anchor the back corners of the bed: the tallest plants on the plan stand there. The plan meets all 17 of the design principles it was checked against, and is Excellent in two categories.
The planner's own design check: 12 Excellent, 5 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 balloon flower 'Sentimental Blue' goes in a border
At 8 in it belongs at the front of a bed. In the planner's ten height classes it is low (6 to 12 in).
Its job: edging. A low, neat plant used in short runs of three or five along the front to finish the edge (or, in a formal bed, in one even row).
It never needs staking, which the tall kind always does. It comes up very late in spring, so mark the spot. Long-lived, and it dislikes being moved.
- Edging
- Containers
- Children's gardens
What to plant with balloon flower 'Sentimental Blue'
Plants recorded as good partners for it, and what each pairing does:
- Threadleaf coreopsis 'Moonbeam': blue against yellow, opposite each other on the colour wheel, in flower together for eight weeks; tall enough (18 in) to stand behind it.
- Lady's mantle: tall enough (18 in) to stand behind it.
- Cheddar pinks 'Firewitch': flowers first, mid May to late June, so the spot is never empty.
Questions about balloon flower 'Sentimental Blue'
Does balloon flower 'Sentimental Blue' need sun or shade?
Balloon flower 'Sentimental Blue' 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 balloon flower 'Sentimental Blue' grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °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 balloon flower 'Sentimental Blue' flower in my zone?
In zone 5 it flowers early July to late 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 late August |
| Zone 6 | Early July to late August |
| Zone 7 | Late June to mid August |
| Zone 8 | Late June to mid 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 balloon flower 'Sentimental Blue' be planted?
10 in (25 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 12 in (30 cm), so a group knits into one patch.
It grows 8 in (20 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many balloon flower 'Sentimental Blue' plants do I need?
At 10 in apart, set out in staggered rows:
- 17 to fill 10 square feet (about 1 m²)
- 13 for a single row 10 ft (3 m) long
- 55 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as runs of three or five along the front (or one even row, in a formal bed).
In the bed above, the planner used eight in two groups.
Is balloon flower 'Sentimental Blue' 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 balloon flower 'Sentimental Blue'?
Balloon flower 'Sentimental Blue' comes from China, Korea, Japan, Russia. These North American natives come closest to doing its job:
- Alpine aster: the same job in a bed and the same size; flowers mid May to late June, purple, lavender or pink, not blue.
- Coral bells 'Firefly': the same job in a bed and the same size; flowers late May to late July, red, not blue.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat balloon flower 'Sentimental Blue'?
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 balloon flower 'Sentimental Blue'?
Balloon flower 'Sentimental Blue' is over by late August. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall.
- Japanese anemone: from mid August to early October, 3 ft tall.
- Sedum 'Autumn Joy': from mid August to mid October, 24 in tall.
What does balloon flower 'Sentimental Blue' look like in winter?
Balloon flower 'Sentimental Blue' 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 Platycodon
- Balloon flower Platycodon grandiflorus
In these guides
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 8 in (20 cm) tall, 12 in (30 cm) wide
- Plant
- 10 in (25 cm) apart
- Height class
- Low (6 to 12 in)
- Place in the bed
- Front
- Flowers
- Early July to late August; hanging bells; blue
- Leaves
- Medium texture, herbaceous; blue-green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun, part sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- None needed
- Family
- Campanulaceae
- Comes from
- China, Korea, Japan, Russia
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.