Birchleaf spirea 'Tor'
Spiraea betulifolia 'Tor' ·
A neat, dense, rounded shrub with small, birch-like leaves, white flower clusters in late spring, and outstanding autumn colour in orange, red and purple.
- Size
- 2½ ft tall, 3 ft wide
- Zones
- 4 to 8
- Light
- Full sun
- Flowers
- Late May to mid June
- Pets
- Not checked
- Job in a bed
- Anchor
A bed built around birchleaf spirea 'Tor'
The planner designed this bed around birchleaf spirea 'Tor' 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 birchleaf spirea 'Tor' stands where it does.
The plants
- 1 Birchleaf spirea 'Tor' × 1, white
- 2 Sea thrift × 8, pink
- 3 Leadwort × 15, blue
- 4 Wild quinine × 3, white
- 5 Brown-eyed Susan × 3, yellow
- 6 Spurge 'Blackbird' × 3, purple leaves
- 7 Daffodil × 6, yellow
- 8 Star of Persia × 3, purple
Why this plant
- The bed's only structure. Shrubs and grasses keep their shape when the perennials die down, and it is the only one here.
Why here
- At the back. At 2½ ft it is seen over leadwort (10 in) in front of it, and has nothing behind it to hide.
- A step in the back row. Next to wild quinine (3½ ft) and brown-eyed Susan (4 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A shrub is seen as an object, and needs clear ground around it.
Why now
- In flower for four weeks. From late May to mid June.
- Part of the bed's peak. With sea thrift and star of Persia in late May: 3 kinds at once. No week has more.
Planned as an English border: 6 of the 7 groups (86%) are drifts, longer along the bed than they are deep. The flowering is at its height from late May, with 3 kinds out together. Neither end outweighs the other: the visual weight is split 53 to 47, left to right.
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 birchleaf spirea 'Tor' goes in a border
At 2½ ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: anchor. A shrub that gives the bed permanent structure. Planted singly, as soon as the front edge is laid; everything else is arranged around it.
It has the virtues of Japanese spirea without the seeding, and far better autumn colour. It keeps its globe shape naturally.
- A tidy, low shrub that needs no pruning
- Autumn colour
- Mass planting and low hedges
What to plant with birchleaf spirea 'Tor'
Plants recorded as good partners for it, and what each pairing does:
- Catmint 'Walker's Low': in flower together for four weeks, from late May; spires rising out of its mound.
- Salvia 'May Night': in flower together for three weeks, from late May; spires rising out of its mound.
- Purple coneflower: takes over when it finishes, flowering from late June.
Questions about birchleaf spirea 'Tor'
Does birchleaf spirea 'Tor' need sun or shade?
Birchleaf spirea 'Tor' grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, of average fertility, and little watering once settled.
What zones does birchleaf spirea 'Tor' 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 birchleaf spirea 'Tor' flower in my zone?
In zone 5 it flowers late May to mid 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 | Late May to mid June |
| Zone 6 | Mid May to mid June |
| Zone 7 | Early May to early June |
| Zone 8 | Early May 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 birchleaf spirea 'Tor' be planted?
2½ ft (75 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3 ft (90 cm), so a group knits into one patch.
It grows 2½ ft (80 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many birchleaf spirea 'Tor' plants do I need?
At 2½ ft apart, set out in staggered rows:
- 2 to fill 10 square feet (about 1 m²)
- 5 for a single row 10 ft (3 m) long
- 6 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, planted singly: it is the bed's structure, and everything else is arranged around it.
In the bed above, the planner used one in one group.
Is there a native plant like birchleaf spirea 'Tor'?
Birchleaf spirea 'Tor' is not native to North America. These North American natives come closest to doing its job:
- Shrubby cinquefoil: the same job in a bed and the same colour; 6 in wider, flowers early June to mid September.
- Sweetspire 'Little Henry': the same job in a bed, the same size and the same colour; flowers early June to early July, medium leaves, not fine.
- Ninebark 'Tiny Wine': the same job in a bed, the same flowering time and the same colour; belongs at the back, not in the middle, 16 in taller.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after birchleaf spirea 'Tor'?
Birchleaf spirea 'Tor' is over by mid June. These start as it finishes and carry the same spot on, so it never goes flat:
- Purple coneflower: from late June to early September, 3 ft tall (a recorded partner).
- Black-eyed Susan: from mid July to mid September, 24 in tall, to stand in front of it and cover its fading stems.
- Butterfly weed: from late June to early August, 24 in tall, to stand in front of it and cover its fading stems.
What does birchleaf spirea 'Tor' look like in winter?
Birchleaf spirea 'Tor' drops its leaves and stands as bare branches. That is when to see its shape, and to prune it if it needs pruning.
More Spiraea
- Bridal wreath spirea Spiraea x vanhouttei
- Japanese spirea 'Goldflame' Spiraea japonica 'Goldflame'
- Japanese spirea 'Little Princess' Spiraea japonica 'Little Princess'
- Japanese spirea 'Magic Carpet' Spiraea japonica 'Magic Carpet'
- Snowmound spirea Spiraea nipponica 'Snowmound'
- Spirea 'Grefsheim' Spiraea x cinerea 'Grefsheim'
- Spirea 'Ogon' Spiraea thunbergii 'Ogon'
- White meadowsweet Spiraea alba
In these guides
- Shrubs under 4 feet for small gardens
- Plants for a white garden
- Plants with purple and burgundy leaves
Every fact on record
- Type
- Shrub
- Size
- 2½ ft (80 cm) tall, 3 ft (90 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- Late May to mid June; dense clusters; white
- Leaves
- Fine texture, deciduous; dark green, red
- Shape
- Rounded, clumping
- Hardy in
- USDA zones 4 to 8
- Light
- Full sun
- 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.