Sweet box

Sweet box: how do you recognise it?

Habit

Dense, rounded, upright shrub 1–1.5 m tall and about as wide; slow-growing.

Leaves

Narrowly oval and pointed, 3–6 cm, leathery and glossy dark green; on the plant all year.

Flowers

Tiny white flowers without true petals, with creamy-white stamens, in small clusters in the leaf axils.

Scent

Sweet and honey-like, remarkably strong for such small flowers; best on mild days.

Fruit

Glossy black berries about 5 mm across, which stay on the shrub for a long time.

Flowering: December–March · Plants: April–May and September–October

Why grow it?

• Scented flowers in the depths of winter, from December to March.
• Evergreen and always neat, even in deep shade.
• Early food for bees and bumblebees on mild winter days.
• Low-maintenance: no pruning needed and seldom troubled by disease.
• Ideal beside a path or by the front door, where you notice the scent every day.

Sweet box: where does it grow best?

• Partial to full shade; in full sun the leaves can yellow or scorch.
• Any ordinary garden soil, from sand to clay, including chalk, as long as it is free-draining and rich in humus.
• Normal moisture; once established it also copes with drier shade under trees.
• Choose a spot beside a path, by the front door or under a window, so you catch the winter scent.
• Allow 60–80 cm between plants, or 40–50 cm for a low hedge.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

1.5 m tall, 1 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Christmas rose: Flowers at the same time in winter shade, in white, pink or purple.
• Snowdrop: Small white flowers at its feet in January–February.
• Witch hazel: Another scented winter flowerer, for a slightly lighter spot behind.
• Ferns: Fresh green leaves in summer, in the same shade.
• Barrenwort: Tough ground cover for dry shade under trees.

Sweet box: when and how to plant it?

Plant in April–May and September–October.

1. Plant in April–May or in September–October.
2. Dig a hole twice as wide as the root ball and mix in some compost or leaf mould.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. Space plants 60–80 cm apart, or 40–50 cm for a low hedge.
5. Water in well straight away, and again in dry spells during the first year.
6. Spread a layer of leaf mould or wood chips around the base.

Care

Watering

Regularly in dry spells during the first year. After that only in long dry periods, especially under trees.

Feeding

Some compost or leaf mould in March–April; no more is needed.

Mulching

A layer of leaf mould keeps the soil cool and moist and tops up the humus.

In a pot

It grows well in a large pot of multi-purpose compost. Water regularly and add a little fresh compost on top each spring.

Tip: Plant it beside a path or by the front door: the flowers are tiny, but on a mild winter day you can smell them several metres away.

Sweet box: when to prune it?

When: No pruning is needed: it stays compact on its own. If you want to tidy it, do so after flowering, in spring.

How:

• Cut out dead, damaged or wayward stems at the base or just above a leaf.
• Rejuvenate an old, bare shrub by removing a few of the oldest stems at ground level each year.
• In winter, pick a few flowering sprigs for indoors: in a small vase they scent a whole room.

Caution: Do not prune in autumn: you would cut off the flower buds for winter.

Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In August–September, take 10 cm cuttings, strip the lower leaves and root them in moist compost under plastic. They root slowly but fairly reliably.

Seed

In spring, squeeze the seed from ripe black berries and sow it straight away in a pot outdoors. Germination is slow.

Rooted pieces

An older shrub sometimes makes shoots around its edge. Dig these up with roots in spring and replant them elsewhere.

Sweet box: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C: no protection is needed in Belgium.
• It flowers in midwinter; hard frost can brown the open flowers, but new buds still open afterwards.
• In a pot: stand it against a wall and wrap it in hessian in hard frost.
• In long spells of dry frost, give a little water on a frost-free day, especially to plants in pots.

Diseases and pests

• Scorched or yellow leaves: Too much sun or drying wind. Move the plant to a shadier spot or give it shelter.
• Box blight: Sweet box can get the same fungus as box: brown spots on the leaves, leaf drop and bare stems. Cut out affected parts, clear up fallen leaves and keep the air moving.
• Slow growth: Normal for this shrub. Compost, mulch and water in dry spells help; extra feed hardly speeds it up.
• Drying out: Limp or withered leaves in the first year or under trees. Water generously and mulch the soil.

Through the year

• January: Full flower and scent. Pick flowering sprigs for indoors.
• February: Flowering. Bees visit on mild days.
• March: Last flowers. Add compost or leaf mould.
• April: Plant. Remove any dead stems.
• May: Plant. Mulch.
• July: Water in dry spells, especially under trees.
• August: Take semi-ripe cuttings.
• September: Plant. Take cuttings.
• October: Plant. Flower buds become visible.
• December: First flowers and scent.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Sweet box belongs to the same family as box, the Buxaceae.
• The flowers have no true petals: what you see are mainly the stamens.
• Male and female flowers grow on the same plant, even in the same cluster; the berries develop from the female flowers.