<em>Aralia</em>: planting, cultivation and care

Botany

The aralias comprise some 70–80 species of trees, bushes and rhizomatous herbaceous perennials. They occur mainly in Asia and North America. Aralia elata is native to eastern and northern Asia (Japan, Korea, Siberia, north‑east China), while Aralia racemosa and A. spinosa come from North America. In the wild, aralias are mostly found in mountain forests. Aralia elata is the species most commonly cultivated in gardens; it is a deciduous tree with very decorative foliage divided into leaflets. It is vigorous and fairly hardy, but dislikes late frosts, which can damage young shoots.

Au niveau botanique, l’Aralia a donné son nom à sa propre famille, celle des Araliacées, which includes more than 1,500 species. This family also groups other plants prized for decorative foliage: Fatsia, Schefflera, Cussonia, Tetrapanax… and, more commonly and less exotically, ivy (Hedera helix)! In fact, the flowers and fruits of Aralia californica resemble those of ivy. Ginseng (Panax ginseng) also belongs to this family.

In French, Aralia elata is called Angélique en arbre du Japon, or Angélique de Chine, because it comes from Asia and its leaves recall those of angelica; but Fatsia japonica is commonly called Japanese aralia… Beware of confusion between these two genera! Only scientific Latin names truly identify these plants. Similarly, Polyscias, a houseplant in the Araliaceae, is sometimes called “Balfour’s aralia”. Aralia spinosa is also called Devil’s walking-stick because of its thorns. In Latin, the species name A. elata means “tall”, while A. spinosa means “spiny”.

Aralia cordata : Illustration botanique

Generally, Aralia elata reaches 5–6 m in height, but at full maturity can attain up to 10 m. It grows fairly quickly, and its crown can be as wide, since it has a spreading habit. The tree has a distinctive silhouette: initially upright, it develops over time into a very elegant, umbrella‑like shape. It is worth planting in isolation to appreciate it fully. The trunk is grey and rough, and bears thorns. Branches are rather thin and elongated, long and sparsely ramified. Depending on training, Aralia can form a single trunk, or several trunks (if you allow suckers to grow). When it produces several stems, the effect is more natural and light, as in coppice.

But aralias are not all woody or tree‑like; some are herbaceous perennials that do not exceed 1.5–2 m in height. Aralia racemosa is a large, spreading, ramified perennial, much lower than the tree species. A. californica is also an elegant perennial with lush foliage.

Aralia has very large divided leaves, composed of numerous leaflets. They are truly decorative and give the plant a lush, exotic aspect. It is thanks to A. elata that it earned the common name Japanese angelica‑tree, or spiny angelica, as its leaves resemble those of angelica, which also bears finely divided foliage. Aralia leaves are bipinnate, twice divided, and borne on a slightly reddish petiole. They are spiny, with small spines along the foliar axes. Leaves of Aralia elata are pubescent on the lower surface. They are tiered and unfold at the top of bare branches, producing an umbrella‑like aspect. This inspired the names of some cultivars, such as ‘Golden Umbrella’ and ‘Silver Umbrella’.

Aralia leaves can reach between 1 m and 1.20 m in length! The leaflets are ovate and small, with a slightly dentate lamina margin, measuring 6–10 cm in length. A single leaf can count up to 80 leaflets!

Aralia leaves are usually green, paler beneath. However, several cultivars offer striking colours! Aralia ‘Sun King’, for example, is distinguished by its superb golden foliage. Leaves can also be variegated, with an irregular cream‑yellow margin on ‘Golden Umbrella’, or white on ‘Silver Umbrella’. These coloured‑leaf varieties are valuable for bringing light into a woodland garden, in shady positions.

In autumn, leaves of Aralia elata turn orange‑yellow to deep purplish red. Aralia is one of those plants that mark the end of the year with flamboyant hues!

Aralia elata is deciduous: its leaves take brilliant autumn colours and then fall; new leaves appear in spring. In general, most aralias grown in gardens are deciduous (A. spinosa, A. californica, etc.), although evergreen species also exist in nature.

Les feuilles de l’Aralia spinosa (photo FD Richards), celles de l’Aralia cordata ‘Sun King’, et celles de l’Aralia elata ‘Silver Umbrella’

Aralia elata flowers in late summer–early autumn, around August–September ( Aralia spinosa flowers somewhat earlier, sometimes from late spring). The plant then bears large, long inflorescences, with a light, airy, vapoury aspect. These are paniculate umbels that group many small flowers and appear on the year’s shoots in terminal position. Panicles of Aralia elata often measure 40–60 cm in length; those of Aralia spinosa are a little larger. Flowering is white or creamy white, sometimes slightly greenish, and the flowering stems are reddish.

Individual flowers are tiny, about 3 mm in diameter, yet very numerous and gathered into large inflorescences! Each small flower has five petals and five stamens bearing pollen. The flowers are melliferous, attracting insect pollinators, particularly bees.

La floraison de l’Aralia elata (photo Katja Schulz), et celle de l’Aralia californica (photo Udo Schmidt)

They are followed by small globose fruits that appear in autumn. These are rounded drupes measuring 4–6 mm in diameter, usually black or dark purple. They are much appreciated by birds, which eat them and thus ensure seed dispersal (zoochory). You can harvest the fruits to extract the seeds and propagate Aralia by sowing. However, these seeds can take a long time to germinate (up to six months!).

The species Aralia racemosa, commonly called clustered Aralia, is attractive in the garden for its superb clusters of dark red–black fruits.

Aralia is valuable for biodiversity, as its flowers are melliferous and its fruits are enjoyed by birds.

Les fruits de l’Aralia cordata (photo Averater), et ceux de l’Aralia racemosa (photo Kristine Paulus)

Aralia elata is suckering: it produces suckers, new shoots that develop from the roots. In this way it can spread and gain ground. The plant can be propagated by taking suckers.

Main Aralia varieties

Most popular varieties

Our favourite varieties

Aralia elata

This species is most commonly cultivated! Appreciated for its majestic, spreading habit and its large, beautifully divided green leaves. In late summer it bears long panicles of white flowers with a vapoury appearance.

• Flowering time October, November
• Height at maturity 5 m

See the product sheet

Aralia cordata Sun King

This variety is remarkable for its superb golden foliage, which brings much brightness to shaded corners of the garden! It also produces cream-white flowers, followed by small black fruits. In addition, young shoots are edible.

• Flowering time September, October
• Height at maturity 1 m

See the product sheet

Aralia elata Silver Umbrella

This Aralia has striking divided leaves, composed of leaflets with green lamina irregularly marginate with white. It is one of the most interesting varieties, offering a majestic silhouette and original foliage, ideal for lightening a slightly shady area of the garden.

• Flowering time September, October
• Height at maturity 5,50 m

See the product sheet

 

Aralia elata Golden Umbrella

This variety is valued for its large leaves made up of green leaflets marginate with cream-yellow. It also produces superb white inflorescences, followed by decorative fruits. It has been awarded the Award of Garden Merit by the Royal Horticultural Society (RHS).

• Flowering time September, October
• Height at maturity 2 m

See the product sheet

Aralia spinosa

This Aralia has very large, strongly divided green leaves, and in summer bears large terminal white inflorescences that are very airy. It is also called spiny angelica or devil's walking stick. It closely resembles Aralia elata.

• Flowering time July to September
• Height at maturity 6 m

See the product sheet

Aralia californica

Very different from other Aralias, this species is not a tree but a large, majestic perennial! Valued for its very decorative, lush, exotic-looking large leaves. It also produces a lovely white flowering in summer, followed in autumn by globose, black–burgundy fruits.

• Flowering time August, September
• Height at maturity 2 m

See the product sheet

Planting

Where to plant?

Plant Aralia preferably in partial shade, as it appreciates bright situations but dislikes scorching sun. Ideally it should have shaded exposure at least during hottest hours of the afternoon. Exposure also depends on location: you can site it in sun if you live in northern France, but prefer partial shade in the south. In short, avoid extremes: scorching sun and heavy, dense shade.

Aralia favours soils rather rich in organic matter, fertile, humus-bearing. At planting, we recommend mixing a little well-rotted compost into the soil. Substrate should be light, deep and free-draining; avoid heavy, compact ground. Aralia also likes cool, slightly moist ground. You can place it near a water feature or pond. However, substrate must remain well-draining. Aralia can tolerate some drought.

It is also important to choose a sheltered spot, as wind can damage foliage.

Aralia are not very sensitive to soil pH; they can grow on acidic or calcareous ground. In general, Aralia is not a demanding plant and can adapt to most garden soils. It also tolerates urban pollution quite well.

Over time Aralia develops a majestic, very elegant silhouette. It is interesting to plant it in isolation, in the middle of a short grass meadow, to showcase its structure! In addition, an isolated planting makes it easy to spot and remove suckers as they appear (which can be more problematic if you plant it right next to a border).

As Aralia grows fairly quickly and spreads by suckers, it can be used to reforest an area rapidly. It can quickly provide tree cover to a garden or space that was previously open and treeless.

Do not hesitate to place Aralia in somewhat secluded parts of the garden that you leave wild and rarely tend. You can let it develop naturally and spread a little; it will form a small grove.

When to plant?

You can plant Aralia in autumn (September – October) or in spring (around April). Plant when weather is relatively mild, outside periods of frost or extreme heat.

How to plant?

1. Start by placing the rootball in a basin of water to rehydrate it.
2. Dig a hole large enough, about three times the size of the rootball.
3. Add some well-rotted compost mixed with garden soil.
4. Place the rootball in the planting hole. Ensure the trunk is straight and that soil level matches original substrate level when it was in the pot.
5. Replace soil around it and firm lightly.
6. Water generously.
7. You can apply a mulch so that the soil stays cool for longer.

Continue watering in the weeks following planting.

Aralia elata

Maintenance, pruning and care

Aralia does not really require maintenance, apart from occasional removal of suckers that appear. It naturally adopts an elegant, well-structured habit and does very well without pruning, but you can also occasionally intervene to remove a few damaged or poorly formed branches, as well as suckers.

If from a very young age you regularly remove suckers, Aralia will form a single trunk. Conversely, if you leave some, it will develop multiple trunks and adopt a lighter, more natural silhouette as a coppice of shoots. Pruning of suckers and branches will therefore influence the overall silhouette of the plant.

You can water it in the year of planting, and during periods of exceptional drought. Likewise, you can occasionally place a little well-rotted compost at its feet to enrich the soil, and incorporate it superficially by simply forking in. However, if soil is too rich and fertile, Aralia may become more fragile and less hardy.

Aralia is not susceptible to diseases and pests. It is sometimes attacked by aphids, but impact on the plant remains fairly low.

Multiplication

We recommend propagating Aralia by removing the suckers it produces. It is also possible to sow seeds and to propagate by root cuttings. Cultivated varieties with variegated, colourful foliage are usually propagated by grafting.

Removing suckers

Aralias regularly produce suckers that develop on roots of the parent plant. They can be separated to obtain new young plants. Do this preferably at the end of winter, around February or March.

1. Choose a well-formed sucker that has grown beside an Aralia.
2. Dig to expose the root system.
3. Cut the roots that connect it to the parent plant.
4. Lift the sucker, preserving as many roots as possible.
5. Prepare soil and replant in a new location.
6. Water generously.

Propagation by root cuttings

Aralia can be propagated by root cuttings in winter (around December–January).

1. Dig at base of an Aralia to expose the roots.
2. Take a segment of root about 8 cm long, cutting it cleanly.
3. Prepare a pot by filling it with a mix of potting compost and sand.
4. Place the root segment vertically in the growing medium so the top of the root is level with the surface.
5. Water lightly.
6. Place the pot under a cold frame.

Sowing

You can harvest the fruits to collect the seeds they contain and sow them in autumn. Preferably use fresh seeds collected recently. They need cold stratification, for example by placing them in the refrigerator for about 4 months. You can then sow them.

1. Prepare a pot by filling it with fine, light potting compost suitable for sowing.
2. Firm surface so it is level and homogeneous.
3. Sow Aralia seeds.
4. Cover lightly with a layer of sifted potting compost, then firm down.
5. Water with a fine spray.
6. Place pot in a bright spot out of direct sunlight, at about 20 °C.

Seeds take a long time to germinate (up to six months!), so be patient. Once seedlings are large enough to handle, prick them out into individual pots. Keep them under cover for winter, at least for the first year. You can then plant them out in the garden (preferably in spring).

Association

With their large, deeply divided leaves, Aralias fit well into exotic-style gardens. You can combine them with other large, generous foliage such as Datisca cannabina, Gunnera, Fatsia japonica, Tetrapanax, Astilboides tabularis… Feel free to add bamboos and lianas: make the most of Akebia quinata, passionflowers… You will thus obtain a kind of luxuriant jungle! We particularly recommend using Aralia californica, that majestic perennial with imposing foliage. Also discover the surprising flowering of Arisaema!

Aralias can be integrated into an exotic, lush garden evoking a true plant jungle! Passiflora caerulea (photo Fdbrumbl), Gunnera manicata (photo Dezidor), Aralia californica (photo Plant Image Library), Akebia quinata (photo Salicyna), Datisca cannabina (photo Peganum), and Arisaema triphyllum (photo Jason Hollinger)

Aralias are also perfect in shade gardens, to recreate a woodland atmosphere that feels very natural (especially when they form several slender trunks and adopt a coppice shoots habit!). Combine them with hostas, ferns, brunneras, Solomon’s seal, sweet woodruff, etc. Discover the superb foliage of Paris polyphylla! Also enjoy the flowering of Anemone nemorosa, bluebells (Hyacinthoides non-scripta), corydalis, Dicentra spectabilis, epimediums, Geranium nodosum… to add small touches of colour! Also discover Cornus canadensis: a white-flowering groundcover with decorative foliage. You will achieve a natural, fresh garden that feels like a walk in the forest! Favour woodland plants that naturally occur in forests. For this type of garden, choose plants that require little maintenance and small flowers that can naturalise. Regarding Aralias, we recommend variegated varieties, as they are ideal for bringing light into the woodland floor! They will brighten the darkest areas of your garden.

They also find their place in a naturalistic garden, to recreate a woodland atmosphere. Geranium nodosum, Brunnera macrophylla (photo Agnieszka Kwiecień, Nova), Aralia spinosa (photo Fritz Flohr Reynolds), Hyacinthoides non-scripta (photo Olivier Pichard), and Polygonatum latifolium (photo Radio Tonreg)

Do not hesitate to pair Aralias with other plants that show lovely autumn colour. Some trees and bushes put on remarkable, flamboyant foliage at the end of the year in shades of red – orange – yellow – purple – bronze… Take advantage of Nandina domestica, Japanese maples, Parrotia persica, Cercidiphyllum japonicum (katsura)… and don’t forget the dogwood Cornus sanguinea, which also offers remarkable reddish‑orange bark in winter. For a beautiful autumn atmosphere, you can also pair Aralia racemosa with other plants that produce decorative fruit: euonymus, Callicarpa, Viburnum opulus, Sorbus aucuparia… This will also have the advantage of attracting birds to the garden!

With its elegant, pared-back silhouette, sparsely ramified, Aralia brings a Japan-inspired style (…especially since A. elata is native to Asia and grows naturally in Japan!) It can easily be integrated into a zen garden. Pair it with Japanese maples, flowering cherries, Cornus kousa, Hakonechloa macra, hostas, horsetails, bamboos… You can add a few cloud-pruned pines and, if desired, structural decorative elements: lanterns, an arbour, a fountain, a wind chime, a jetty, stepping stones… but without excess. Also leave plenty of room for mineral elements by adding gravel and a few rocks with interesting shapes. This will create an atmosphere suited to meditation.

Also remember that Aralia is magnificent as a solitary specimen! This really highlights its silhouette while making it easy to control suckers.

Did you know?

• Edible and medicinal plant

Several species of Aralia are edible and eaten in some Asian countries. Young shoots of Aralia cordata (though A. elata is also edible) are mainly used; they are harvested in spring while still tender. They can then be blanched and eaten like asparagus, or fried. Moreover, Aralia cordata is also called Aralia edulis (a synonym), and this species name, edulis, means “edible” in Latin. Similarly, fruits of Aralia racemosa are edible! The root of this species is also medicinal, effective against breathing ailments, asthma, colds and coughs. It is mainly used in homeopathy.