Sweet box
Sarcococca hookeriana var. humilis · Buxaceae
A low, slowly spreading evergreen with narrow, glossy leaves and tiny white flowers, hidden among them in late winter, that scent the air for metres around.
- Size
- 18 in tall, 3 ft wide
- Zones
- 6 to 8
- Light
- Part shade to shade
- Flowers
- Early February to late March
- Pets
- No toxicity recorded
- Job in a bed
- Carpet
A bed built around sweet box
The planner designed this bed around sweet box when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why sweet box stands where it does.
The plants
- 1 Sweet box × 5, white
- 2 Bleeding heart 'King of Hearts' × 5, pink
- 3 English primrose × 14, yellow
- 4 Astilbe 'Purple Candles' × 3, purple
- 5 Korean feather reed grass × 1, pink
- 6 Ghost fern × 3, silver leaves
- 7 Snowdrop × 12, white
- 8 Striped squill × 12, blue
Why this plant
- The only dense clusters. The others are bells, open bowls and plumes. Shape reads at a distance, where colours blur.
- A classic partner for snowdrop. Both are on this plan. A pairing gardeners have proved outranks a general rule.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does Korean feather reed grass.
Why here
- Under the taller plants. It runs back between them as living mulch: there its job is to cover the soil, not to be looked at.
- 5 plants in 3 groups (3, 1 and 1). Seen again further along, the same plant ties the bed together.
- Beside snowdrop. A recognised partner: the planner puts such plants together where it can.
Why now
- In flower for 7 weeks. From early February to late March.
- Opens the season. For its first four weeks nothing else on the plan is in flower.
- The only leaves in winter. From November to March it is what there is to look at.
Planned as an English border: 6 of the 7 groups (86%) are drifts, longer along the bed than they are deep. The back corners are held by Korean feather reed grass and astilbe 'Purple Candles', the tallest plants on the plan. The front edge is finished with English primrose and bleeding heart 'King of Hearts'.
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 sweet box 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: carpet. A groundcover planted in threes and fives to cover the soil: along the front, and just behind it.
Its vanilla scent on a cold February day comes as a surprise, because the flowers are almost invisible. It is one of the best evergreen carpets for dry shade.
- Winter fragrance beside a path or door
- Evergreen groundcover in deep shade
- Dry shade under trees
What to plant with sweet box
Plants recorded as good partners for it, and what each pairing does:
- Lenten rose: bold leaves against its medium ones.
- Christmas fern: its dark green leaves are a setting for the flowers, before and after.
- Snowdrop: in flower together for three weeks, from early March; low enough (6 in) to stand in front of it; happy in the same moist soil.
Questions about sweet box
Does sweet box need sun or shade?
Sweet box grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light). It is one of the few that also put up with deep shade.
It wants soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.
What zones does sweet box grow in?
USDA zones 6 to 8. It is hardy to zone 6, which means it survives winter nights down to about 0 °F (−18 °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 sweet box flower in my zone?
In zone 5 it flowers early February to late March. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 6 | Early February to mid March |
|---|---|
| Zone 7 | Late January to early March |
| Zone 8 | Mid January to early March |
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 sweet box be planted?
24 in (60 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 18 in (45 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many sweet box plants do I need?
At 24 in apart, set out in staggered rows:
- 3 to fill 10 square feet (about 1 m²)
- 6 for a single row 10 ft (3 m) long
- 10 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 five in three groups.
Is sweet box 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 sweet box?
Sweet box comes from China. These North American natives come closest to doing its job:
- Lowbush blueberry: the same job in a bed and the same colour; 6 in narrower, flowers early May to late May.
- Creeping mahonia: the same job in a bed; 6 in shorter, 6 in narrower.
- Cliff green: the same job in a bed; 6 in shorter, grown for its leaves, not its flowers.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat sweet box?
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 sweet box?
Sweet box is over by late March. These start as it finishes and carry the same spot on, so it never goes flat:
- Lenten rose: from late March to early May, 18 in tall (a recorded partner).
- Polyanthus primrose: from late March to mid May, 8 in tall, to stand in front of it and cover its fading stems.
- Reblooming azalea: from mid April to mid May, 3½ ft tall.
What does sweet box look like in winter?
Sweet box keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone. It is grown for winter fragrance beside a path or door as well.
More Sarcococca
- Christmas box Sarcococca confusa
In these guides
- Plants for deep shade
- Pet-safe plants for shade
- Groundcover plants
- Evergreen shrubs for structure
- Shrubs under 4 feet for small gardens
- The first flowers of spring
- Plants for a white garden
Every fact on record
- Type
- Shrub (groundcover)
- Size
- 18 in (45 cm) tall, 3 ft (90 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Early February to late March; dense clusters; white
- Leaves
- Medium texture, evergreen; dark green
- Shape
- Mat-forming, spreading
- Hardy in
- USDA zones 6 to 8
- Light
- Part shade, shade
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Buxaceae
- Comes from
- China
- Stands up to
- Deep shade
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.