Rhodocoma: Planting, Growing and Caring

Botany

Rhodocoma comprises 8 species native to South Africa, mainly from the Cape region. They are found particularly in the fynbos, a characteristic plant formation with a Mediterranean climate and soils poor in organic matter, where many Proteaceae, Restionaceae and Ericaceae grow, along with succulents, bulbous plants, Asteraceae… Rhodocoma are still rare plants in gardens, despite their beautiful ornamental qualities. The main species in cultivation are Rhodocoma capensis and Rhodocoma gigantea.

Rhodocoma is one of those plants commonly called Restio, like Elegia capensis or Thamnocortus, as they belong to the Restionaceae family. These are monocotyledonous herbaceous plants, comprising over 400 species native to the Southern Hemisphere (South Africa, Australia, New Zealand, Madagascar, Chile…). Discover our full range of restios by clicking here.

Etymologically, the name restios comes from the Latin restis: “rope”, as the very strong stems of some species could be used to make ropes. Similarly, some restios were used to make thatched roofs or brooms… As for the name Rhodocoma, it comes from the Greek rhodo: rose, and kome: hairs, alluding to the pink, feathery flowers of female plants. Rhodocoma capensis was named as it originates from the former Cape Province in South Africa (which today corresponds to about half of South Africa’s territory).

Detail of Rhodocoma capensis stems. They do not bear true leaves: these are reduced to brown scales at the nodes. (photos: Krzysztof Golik / Krzysztof Ziarnek / Adobe Stock)

Rhodocoma are large perennials with a very dense habit, forming clumps of upright stems. These stems are long, sturdy, and beautifully flared, giving the plant a very elegant appearance. They are arched, leaning in young plants, but become increasingly straight and erect over time. Their silhouette resembles reeds or tall grasses like Miscanthus. Rhodocoma capensis grows between 1 and 2 m tall, while Rhodocoma gigantea reaches up to 2.50 m – 3 m in height. Their stems are sturdy with well-marked nodes, like bamboos, from which numerous fine, feathery, very dense branches emerge. This gives Rhodocoma a very graphic and airy style. Like horsetails, Rhodocoma do not have true leaves: they are reduced to small brown scales at the nodes. The green stems perform photosynthesis. The absence of leaves is an adaptation to drought: it limits evapotranspiration and thus water loss.

Rhodocoma flower in late spring or early summer, between May and July, depending on the climate and species cultivated. Rhodocoma plants are either male or female, producing different inflorescences. Female inflorescences are short and upright, with flowers bearing pink, feathery styles, while male inflorescences are long and arched, with brown spikelets trailing towards the ground.

As with other Restionaceae, pollination is wind-borne, carrying pollen from male plants to female flowers. This also explains why Restio flowers are discreet, not very colourful or fragrant… as flower colours and scents serve solely to attract insects and other animals responsible for pollination.

Rhodocoma produces very small oval brown seeds. When mature, they fall to the ground and wait for suitable conditions before germinating. In South Africa, fires are frequent in the fynbos: Rhodocoma have naturally adapted to this, so their seeds require fire to germinate.

Rhodocoma roots are fragile and dislike being moved. Therefore, it’s best to choose its location carefully before planting in the garden.

Male inflorescences of Rhodocoma gigantea and seeds of Rhodocoma capensis. (photos: Krzysztof Ziarnek / Omar Hoftun)

The main varieties

The Most Popular Varieties

In cultivation, you’ll mainly find the two species Rhodocoma capensis and Rhodocoma gigantea.

Rhodocoma capensis

Native to the Cape Province in South Africa, this is a very beautiful rhodocoma that forms dense clumps of upright stems with graceful arches. Relatively hardy, it can withstand temperatures down to -12°C once well established.

• Flowering time June, July
• Height at maturity 1,50 m

See the product sheet

Rhodocoma gigantea - Restio

As its name suggests, this is a monumental rhodocoma, reaching up to 2.50m, sometimes even 3m in height. It forms upright clumps of stems divided into very fine, light green branches. It is less cold-hardy than Rhodocoma capensis.

• Flowering time July, August
• Height at maturity 2,50 m

See the product sheet

Also discover other Restios, which are very similar to Rhodocoma.

Planting

Where to plant?

Native to South Africa, Rhodocoma thrives in warmth and sunlight. It grows in the fynbos, where soils are poor in organic matter, rather acidic, clayey or sandy. In the garden, find it a spot in full sun (though it will also tolerate light shade). Plant it in well-drained soil, preferably poor, neutral or acidic. It dislikes heavy, compacted soils that are waterlogged.

Rhodocomas appreciate mild climates, not too cold in winter. They are ideal plants for coastal gardens, especially as they withstand wind and sea spray without issue. Once established, they can nevertheless tolerate temperatures dropping between -8 and -10°C in well-drained soil (or even down to -12°C for Rhodocoma capensis).

Choose their location carefully as once planted, Rhodocomas dislike being moved. Rhodocomas will find for example their place in an exotic border, where their silhouette adds height and structure, or in a garden of southern hemisphere plants. They are highly decorative, architectural plants.

Rhodocomas also adapt well to container cultivation: this makes it easy to bring them under cover in winter and place them on a terrace for the rest of the year, where they will effortlessly create an exotic, graphic atmosphere. For pot cultivation, we recommend Rhodocoma capensis, which is more compact than R. gigantea.

When to plant?

We recommend planting Rhodocoma in spring, around April. In regions with low frost risk, such as the Mediterranean coast, it can also be planted in autumn.

How to plant?

When planting a Rhodocoma, handle it carefully to avoid disturbing its roots too much.

In the ground:

1. Start by placing the rootball in a basin of water to rehydrate it.
2. Meanwhile, dig a planting hole about three times the size of the rootball.
3. Add back some soil mixed with coarse sand to improve drainage.
4. Remove the Rhodocoma from its pot and plant it.
5. Backfill with substrate all around.
6. Water generously.

In pots:

1. Take a large pot with drainage holes.
2. Place a drainage layer at the bottom, such as gravel or clay pebbles.
3. Then add a mix of compost, garden soil and sand.
4. Position the Rhodocoma in the new pot, right in the centre.
5. Fill in with substrate, then firm lightly.
6. Water generously.

Rhodocoma capensis

Maintenance

Rhodocomas require very little maintenance and are not susceptible to diseases or parasitic issues. However, they will appreciate some watering during summer droughts. Preferably use rainwater rather than tap water, which may be too hard for them. Similarly, don’t hesitate to apply a mulch around the clump, such as pine bark, to keep the soil moist for longer.

In winter, you can protect the Rhodocoma from the cold by wrapping it in horticultural fleece and adding a thick layer of mulch around the base of the clump.

If you notice any stems damaged by frost in winter, you can prune them back hard.

Caring for a potted Rhodocoma:

If grown in a pot, consider moving it to a frost-free shelter during winter. In spring, place the Rhodocoma back on your patio in full sun.

When potted, remember to water it regularly, as the growing medium dries out faster than in the ground, but avoid letting water stagnate in the saucer. Reduce watering in autumn and winter.

We recommend repotting the Rhodocoma every two years. This helps refresh the growing medium and gives it more space to develop. In years when you don’t repot, top-dress by removing a little of the old medium from the top few centimetres and replacing it with fresh compost.

Propagation

Sowing

Rhodocoma can be propagated from seeds. However, these are not easy to harvest as they are small and quickly fall to the ground as soon as they are ripe, and they require specific conditions for germination.

In South Africa, fires are regular in the fynbos, and Rhodocomas have adapted accordingly. It is the passage of fire that breaks the dormancy of their seeds and allows them to germinate. You will therefore need to mimic fire, for example by mixing ashes into the substrate.

1. To encourage germination, soak the seeds for 24 hours in water to which you have added a teaspoon of ashes.
2. Fill a pot with special sowing compost (or a mix of compost and sand), to which you will add a little ash.
3. Lightly firm and level the surface.
4. Sow the seeds.
5. Cover them with a thin layer of substrate.
6. Water.

Ensure the substrate remains slightly moist until germination occurs.

Division of Clumps

Rhodocoma can also be divided in late winter or early spring.

1. Choose a large, well-developed young plant.
2. Dig around it to lift it.
3. Separate it into several clumps using a spade or pruning shears. Each should be fairly large, as Rhodocoma takes a long time to develop after division.
4. Replant in a new location or in a pot.

Association

With their imposing silhouette, Rhodocomas are perfect for creating an exotic-style garden. Pair them with lush vegetation plants such as palm trees and bamboos, the Musa basjoo banana plant, the Datisca cannabina, the Fatsia japonica and the Tetrapanax. This will create a stunning plant setting reminiscent of a tropical jungle! For flowering plants, opt for warm hues (yellow, orange, red, purple…): consider kniphofias, crocosmias, cannas and daylilies, for example.

In regions with a relatively cool climate, such as north of the Loire, you can grow Rhodocoma in pots and place them on your terrace to create a beautiful summer display. Choose the Rhodocoma capensis, and place the pot on the terrace alongside other container plants that need winter protection, such as the Gloriosa superba, the Strelitzia reginae, as well as palm trees, passionflowers, lantanas, abutilons and cordylines. In autumn, you can move all these plants to a frost-free, well-lit shelter to protect them from the cold during the winter months.

Rhodocoma is perfect for creating an exotic garden with other Australasian plants. Kniphofia ‘Fiery Fred’, Rhodocoma capensis, Anigozanthos, Dietes grandiflora, Leptospermum scoparium (photo J. Tann) and Libertia ixioides ‘Taupo Blaze’ (photo M. Hansen)

Rhodocoma is ideal for creating an Australasian plant garden. These include plants native to Australia, New Zealand and South Africa, adapted to hot, dry climates and poor, acidic soils. Consider, for example, proteas such as Grevillea, Leucadendron and Protea. Take advantage of the highly graphic foliage of the dasylirion, Cordyline australis, Libertia ixioides and Phormium tenax! For flowering plants, consider the Watsonia, Dietes grandiflora, Anigozanthos flavidus and Leptospermum. This will give you a garden that is both striking and exotic!

For more advice and information, check out our guide ‘Planting and Growing Australasian Plants’.