Spindle, Euonymus: planting, pruning and care

Description and botany

Genus Euonymus, sometimes spelled Evonymus, is better known as spindle. It includes more than 175 species of trees, shrubs and rooting plants (that spread by producing suckers) and even creeping forms. Most grow in Northern Hemisphere, the most notable (Euonymus japonicus, alatus…) ranging from the Himalayas to the Far East via Southeast Asia. They also occur in North America (4 species), Australasia and Madagascar. But Europe has its own species, the European spindle, Euonymus europaeus, widespread from Finland to western Asia Minor, nicknamed the ‘bishop’s cap’ because of the shape of its fruits.

Euonymus europaeus, botanical illustration

Genus Euonymus, belonging to family Celastraceae, is characterised by simple leaves 5–12 cm long, opposite but sometimes alternate and generally with toothed margins and a short petiole. Among members of this family is Celastrus, an ornamental climbing shrub noted for its orange fruits. Shape of the lamina is fairly typical, ovate to lanceolate, sometimes acuminate. Spindles divide into two groups with different uses: evergreen species and deciduous species.

Evergreen spindles (Euonymus japonicus, fortunei…) have a leathery, waxy texture and dense, often colourful foliage, valued for hedging, rockery planting or as a specimen focal point.

Deciduous species (Euonymus alatus, europaeus, bungeanus), with ordinary leaves, make up for it in autumn by producing superb foliage colours from purple and scarlet to orange, combined with the colours of the fruits.

Twigs, brown or green, are smooth or quadrangular. Sometimes corky outgrowths cover the stems, giving a winged appearance to the bark as seen on Euonymus alatus or E. phellomanus.

The flowers, formed of four petals, are grouped in cymes at the base of current-year shoots and are rather insignificant because of their small size, greenish or yellowish, sometimes pinkish hue and almost complete lack of scent. Flowering occurs between May and August depending on species, once leaves have developed.

The fruits are, however, remarkable: a pinkish or red capsule that usually splits into four valves reveals 3–4 seeds brightly coloured orange, vermilion or coral red. These seeds bear a fleshy, oleaginous covering, highly nutritious for birds, called an ‘aril’, which aids seed dispersal in their droppings. Seeds remain attached to the capsule for some time.

Berries of some spindle species are highly decorative: Euonymus planipes, Euonymus europaeus, Euonymus phellomanus, Euonymus europaeus.

Asian spindles caught the interest of young naturalist Victor Jacquemont (1801–1832), sent by the Paris Museum on a first mission to Kashmir and Punjab in 1830. Eunonymus japonicus became popular in Europe in the 19th century. It provides a hard, robust wood used for making spindles for spinning wool, but it is best known to artists for wood converted into charcoal used for sketching without marking the paper (hence the name ‘fusain’). Its roots produce a gutta-percha–type latex also extracted from other trees in the Sapotaceae family.

Main species and varieties

Spindles offer a surprising range of habits. Euonymus fortunei, the best-known and arguably most popular of all, can spread up to 6 m and even climb trees like an ivy, helped by its climbing roots. However, its cultivars are usually more compact and rarely exceed 1 m of spread. These are well suited to container growing or creating topiary even if their growth is a little faster than box.

Japanese spindle (Euonymus japonicus) forms a small evergreen tree spreading 3 to 5 m high, although its variegated cultivars rarely exceed 1.50 m in any direction. Its deciduous counterpart, the European spindle (Euonymus europaeus), also provides ideal shade in a small garden, with a spreading habit of 3 to 5 m.

To find which variety will best suit your garden, see this article: “Spindle: which variety to choose?“

Most popular varieties

Euonymus japonicus Aureus - Japanese Spindle

This cultivar with evergreen foliage variegated with yellow is perfect to brighten the garden even in winter. Ideal for creating pretty, colourful low hedges, it can also be planted as a specimen or in a mixed border. More susceptible to severe frosts than the species.

• Flowering time June to August
• Height at maturity 1,50 m

See the full description

Euonymus europaeus Red Cascade - European Spindle

This small tree forms a rounded clump with drooping branches borne on several close trunks. It remains fairly inconspicuous for most of the season until foliage turns rosy red in autumn, accompanied by a profusion of bicoloured pink and bright orange fruits. Ideal for composing informal hedges with a rustic feel or for planting as a specimen thanks to its striking habit.

• Flowering time May
• Height at maturity 3 m

See the full description

Euonymus fortunei Emerald n gold - Spindle

This small evergreen shrub bears fine, very bright foliage and a compact semi-spreading habit 40-50 cm in diameter. Suitable for rockeries, as a groundcover, for forming low clipped hedges and borders, and for filling a container, whatever the aspect.

• Flowering time June, July
• Height at maturity 60 cm

See the full description

Our favourite varieties

Euonymus japonicus Microphyllus Aureovariegatus - Japanese Spindle

At a time when box is looking sad, victim of attacks by box tree moth and other diseases, this very compact variety is timely. Very tolerant of pruning and slow-growing, its small leaves are evergreen and dark green edged with golden yellow.

• Flowering time June to August
• Height at maturity 1,20 m

See the full description

Euonymus alatus Compactus - Winged Spindle

This Asian deciduous shrub, with a table-like habit 1.50 to 2 m in diameter, is recognised by its winged branches. It literally bursts into spectacular bright garnet tones in autumn. Its vivid pink fruits with orange seeds illuminate the green foliage in late summer.

• Flowering time June, July
• Height at maturity 1 m

See the full description

Euonymus japonicus Bravo - Japanese Spindle

Hardier than ‘Aureomarginatus’, this evergreen variety is slightly more vigorous and very elegant with erect branches bearing 4-5 cm leaves, green splashed with silver and edged in white. Used to form medium to low hedges, it pairs perfectly with other shrubs and dwarf conifers, with a spread not exceeding 1 m.

• Flowering time June to August
• Height at maturity 2 m

See the full description

Planting spindle trees

Where to plant?

Plant Euonymus in a sheltered, sunny position. Variegated forms, however, will look better in partial shade and will also provide a pretty creamy or golden touch of brightness. Solid-green forms tolerate more shade than variegated ones.

Deciduous Euonymus (europaeus, alatus, grandiflorus…) are very hardy and can be planted throughout France except in dry Mediterranean climates.

Among evergreen forms, fortunei tolerates severe cold down to -28°C. japonicus, by contrast, is more fragile; avoid exposing it to temperatures below -12°C (zone 8 maximum), although it tolerates sea spray perfectly.

Evergreen Euonymus grow in neutral to calcareous soil, preferably rather rich and cool, whereas deciduous Euonymus, indifferent to pH, will do well in poor, free-draining soil that stays relatively cool in summer. In all cases, avoid waterlogged soils even though Euonymus appreciate some coolness around the roots. Add a layer of gravel to the bottom of the planting hole if necessary or plant on a slope to improve drainage.

Stunning autumn colour of Euonymus alatus ‘Compactus’.

When to plant?

Although Euonymus can be planted at any time of year, it is best to do so from October through to March or April. Avoid working during frosts or periods of very hot weather.

How to plant?

Allow enough space around each plant – 1 m² for groundcover species – so they can fill out harmoniously. In a border or hedge, space Euonymus plants 1.5 to 2 m apart from one another and from other trees or shrubs, as their dense foliage and vigorous growth could smother nearby plants. Dig a trench rather than individual holes when creating a hedge.

Sarmentous groundcover species such as Euonymus fortunei ‘Minimus’ (15–20 cm high) should be planted 50–80 cm apart to quickly cover the soil with their fine foliage.

To plant:

1. Moisten the rootball to aid establishment.
2. Dig a planting hole, two to three times the size of the rootball. Add a shovelful of well-rotted compost.
3. Place the plant in the planting hole.
4. Refill with soil and firm lightly.
5. Water.
6. Spread a layer of mulch around the base to help keep roots cool. This will also reduce weed growth. 

For container growing, place a 3–4 cm drainage layer in the bottom of the pot (gravel, broken pottery, etc.). Add a mix of 1/3 soil, 1/3 potting compost and 1/3 coarse sand.

Small evergreen Euonymus lend themselves well to container culture, here: Euonymus fortunei ‘Emerald Gaiety’, Delphinium ‘Blue Diamonds’, Scaevola ‘White Blessing’.

Pruning and care

Pruning Euonymus

Prune deciduous Euonymus in winter to better assess silhouette using pruning shear. Remove misplaced branches that cross or are damaged. For Euonymus grown as standards, remove low branches arising from trunk

Euonymus used in borders or as topiary should be trimmed with shear or bonsai scissors in April and autumn, or even at planting. This will be more a pinch than a pruning: shorten leafy shoots by a few centimetres without cutting back to bare wood. Hedging plants can be trimmed with shear or a hedge trimmer twice a year, in April and August.

Care

Euonymus are trees or shrubs easy to grow and require very little maintenance. Once established, they need no watering, but it is preferable to water regularly during first year and, thereafter, in dry spells. Likewise, if you grow Euonymus in a pot or container, water once or twice a week, as potting mix dries faster than in soil.

Apply mulch around base will help limit weed growth and protect shrub from drought and frost.

Japanese Euonymus are most sensitive to cold. If growing these varieties, protect them during first few years using a fleece and by laying a thick layer of mulch on the soil. In case of snow, shake branches of evergreen Japanese Euonymus to remove it and prevent branches from breaking under its weight.

Possible pests and diseases

Evergreen euonymus are sometimes attacked by mealybugs that form cottony masses or small dark shields on stems or under leaves. Treat with white oil or introduce natural predators such as the ladybird Cryptolaemus montrouzieri.

Powdery mildew leaves a white dusting on shoots and leaves of Japanese euonymus, especially when the first hot weather arrives. Quickly cut out affected parts to prevent spread. If symptoms recur, apply sulphur to foliage. If your shrub is repeatedly affected, we recommend moving it to a sunnier, better-ventilated spot.

Winged euonymus branches are very striking, especially in mid-winter.

Multiplying spindle: propagation by cuttings and sowing

Spindles are propagated by sowing or by propagation by cuttings. Propagation by cuttings is the best technique for evergreen varieties and sowing for deciduous ones. It is also possible to divide clumps of suckering spindles.

Take cuttings from spindle

Evergreen spindles are cut in August using semi-ripe shoots while for deciduous spindles wait from September to November and use ripe shoots.

1. Prepare a pot by filling it with potting compost mixed with sand, or take cuttings directly into light soil after loosening it with a fork, then moisten the substrate.
2. Take a shoot about 10 cm long from a current-year growth, taking care to remove it at a fork so as to include a “heel” (end of parent shoot). It must be healthy and free of disease.
3. Remove leaves near base of cutting, and trim remaining leaves to reduce leaf area. Leave only a few leaves at top if still present.
4. Dip base of stem in rooting hormone.
5. Make a hole in substrate using a pencil or wooden stick.
6. Insert cutting into hole and firm substrate gently around it to remove air pockets and ensure good contact between compost and cutting.
7. Cover pot with a plastic bag to maintain humid atmosphere, especially if leaves are present. Vent occasionally to prevent development of cryptogamous diseases.
8. Place pot under a cold frame in a warm, bright spot but sheltered from direct sun.
9. Pot on rooted cuttings in spring into a richer medium and grow them at least until following spring before planting out permanently.

Sowing spindles

Sowing of deciduous spindles often occurs naturally but you cannot be sure of obtaining original selected variety. Use fresh seed where possible and consider cold stratifying them (exposure to cold in sand) if sowing in spring to break dormancy.

1. Harvest seeds in autumn when capsules open and remove aril (fleshy part) which is brightly coloured.
2. To stratify seeds, place them in a tray filled with equal parts potting compost and sand, or sand only. Moisten substrate and mix in seeds. Enclose everything in a plastic bag, then place in cold (between 0 and 5 °C), for example in fridge, for two to three months. Seeds may sometimes germinate while still cold; in that case lift them as they appear and pot into pots.
3. Remove seeds from fridge.
4. Prepare a pot by filling it with a seed-sowing compost.
5. Sow seeds about 1 cm deep and place under cold frame.
6. Water with a fine mist.

Continue to water regularly but without excess so substrate stays moist. Pot on young seedlings a few months after germination. After one to two years you can plant them in their final position.

Companion planting with spindle

Euonymus can create very different scenes depending on species, as size, habit and leaf colour are highly variable. Dwarf or medium-sized evergreen varieties, clipped or not, are used in rock gardens and vicar’s gardens to replace box in particular, and for topiary.

Place deciduous Euonymus such as Evonymus europaeus ‘Red Cascade’ at the back of a border of asters and Japanese anemones so they can frame the scene in autumn, or within a loose hedge.

An example of an autumnal combination: Euonymus alatus, Acer palmatum, Pennisetum alocuperoïdes ‘Hameln’, Miscanthus sinensis ‘Malepartus’, Sedum ‘Autumn Joy’, Heucheras and various Asters. (Friedrich Strauss – Biosphoto)

Japanese euonymus is an ideal partner for forming windbreak hedges by the coast, as it dislikes confined sites and severe winters.

The trailing euonymus such as fortunei ‘Emerald Gaiety’ has rapid growth that allows it to carpet the ground of a bed while brightening it with olive-green and cream tones, turning pink during winter. It creates a pretty colourful scene alongside bronze fennel or dwarf roses. It is also attractive to train the stems up the trunk of a large leaning tree to about 3 m high or to use it in a hanging basket paired with a bright pink cyclamen.

An example of a planting combination: Euonymus fortunei ‘Emerald Gaiety’, Nicotiana alata, Lythrum salicaria, Stachys byzantina, Hydrangea quercifolia ‘Snow Queen’.