Serbian bellflower
Campanula poscharskyana ·
Long trailing stems covered in starry, lavender-blue flowers in early summer. A vigorous mat for walls, steps and the edges of paths.
- Size
- 8 in tall, 24 in wide
- Zones
- 3 to 8
- Light
- Full sun to part shade
- Flowers
- Late May to mid July
- Pets
- Not checked
- Job in a bed
- Carpet
A bed built around Serbian bellflower
The planner designed this bed around Serbian bellflower when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part sun. It chose the other plants from the 708 that suit those conditions, and says below why Serbian bellflower stands where it does.
The plants
- 1 Serbian bellflower × 6, lavender
- 2 Bloody cranesbill 'Max Frei' × 3, pink
- 3 Swamp milkweed 'Ice Ballet' × 3, white
- 4 Coneflower 'Magnus' × 5, pink
- 5 Inkberry 'Gem Box' × 1, dark green leaves
- 6 Bergenia 'Winter Glow' × 3, red
- 7 Red spider lily × 5, red
- 8 Surprise lily × 12, pink
Why this plant
- The only bells. The others are open bowls, flat plates, daisies and others. Shape reads at a distance, where colours blur.
- The only lavender.
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 75% of the edge.
- 6 plants in 2 runs (3 and 3). Short runs, with other plants between, make the edge a frame, not a ruled line.
Why now
- In flower for 7 weeks. From late May to mid July.
- Part of the bed's peak. With bloody cranesbill 'Max Frei', swamp milkweed 'Ice Ballet' and coneflower 'Magnus' in early July: 4 kinds at once. No week has more.
Planned as an English border: 5 of the 6 groups (83%) are drifts, longer along the bed than they are deep. Bergenia 'Winter Glow' is the first into flower, in mid April, and red spider lily the last to finish, in early October. The most in flower at one time is 4 kinds, from early July.
The planner's own design check: 13 Excellent, 4 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 Serbian bellflower 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: carpet. A groundcover planted in threes and fives to cover the soil: along the front, and just behind it.
Tougher and more shade-tolerant than most bellflowers, and useful for softening hard edges. It can overrun small neighbours, so pair it with plants of its own vigour.
- Trailing over walls and steps
- Groundcover in part shade
- Softening paving
What to plant with Serbian bellflower
Plants recorded as good partners for it, and what each pairing does:
- Lady's mantle: in flower together for six weeks, from late May; tall enough (18 in) to stand behind it.
- Hosta: its green leaves are a setting for the flowers, before and after; bold leaves against its medium ones; spires rising out of its mound.
- Coral bells: its burgundy leaves are a setting for the flowers, before and after.
Questions about Serbian bellflower
Does Serbian bellflower need sun or shade?
Serbian bellflower grows in full sun (6 or more hours of direct sun a day), part sun (4 to 6 hours of sun, including some afternoon sun) and part shade (2 to 4 hours of sun, mostly in the morning).
It wants ordinary well-drained soil, of average fertility, and little watering once settled.
What zones does Serbian bellflower 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 Serbian bellflower flower in my zone?
In zone 5 it flowers late May to mid July. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 3 | Mid June to mid July |
|---|---|
| Zone 4 | Early June to mid July |
| Zone 5 | Late May to mid July |
| Zone 6 | Late May to mid July |
| Zone 7 | Mid May to early July |
| Zone 8 | Early May to early 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 Serbian bellflower 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 8 in (20 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Serbian bellflower 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 threes and fives, along the front and just behind it.
In the bed above, the planner used six in two groups.
Is there a native plant like Serbian bellflower?
Serbian bellflower is not native to North America. These North American natives come closest to doing its job:
- Creeping woodland phlox: the same job in a bed and the same colour; 6 in narrower, flowers late April to late May.
- Woodland strawberry: the same job in a bed; 6 in narrower, flowers early May to late August.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Will Serbian bellflower spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads steadily by creeping stems. It is easy to pull out, but needs a firm edge.
What flowers after Serbian bellflower?
Serbian bellflower 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.
- Black-eyed Susan: from mid July to mid September, 24 in tall.
- Ornamental onion 'Millenium': from mid July to late August, 18 in tall.
What does Serbian bellflower look like in winter?
Serbian bellflower holds some of its leaves into winter, more in a mild year or a sheltered spot, and they look tired by March. Cut the old ones off as new growth starts.
More Campanula
- Bellflower 'Dickson's Gold' Campanula garganica 'Dickson's Gold'
- Bellflower 'Kent Belle' Campanula 'Kent Belle'
- Bellflower 'Sarastro' Campanula 'Sarastro'
- Carpathian bellflower Campanula carpatica
- Carpathian bellflower 'Blue Clips' Campanula carpatica 'Blue Clips'
- Clustered bellflower Campanula glomerata
- Dalmatian bellflower Campanula portenschlagiana
- Fairy thimbles Campanula cochleariifolia
- Harebell Campanula rotundifolia
- Milky bellflower Campanula lactiflora
- Peach-leaved bellflower Campanula persicifolia
- Spotted bellflower 'Cherry Bells' Campanula punctata 'Cherry Bells'
In these guides
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial (groundcover)
- Size
- 8 in (20 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Low (6 to 12 in)
- Place in the bed
- Front
- Flowers
- Late May to mid July; hanging bells; lavender
- Leaves
- Medium texture, semi-evergreen; green
- Shape
- Mat-forming, spreading
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun, part sun, part shade
- Soil
- Average, well-drained
- Water
- Low
- Feeding
- None needed
Not yet checked against an outside reference: its figures rest on general horticultural knowledge. 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.