Copernicia: Planting and Care

Description and Botany

The Copernicia, commonly known as “wax palm”, belongs to the vast Arecaceae family, which includes all palm trees. The genus comprises 22 species and hybrid varieties native to South American savannas and forests, from Cuba, Argentina, Brazil, or Bolivia. In cultivation, in our gardens, we mainly encounter the Copernicia alba, the only species capable of withstanding temperatures down to -7°C. This is why this palm tree can only be grown in the ground in the mildest gardens of our country, along the Mediterranean coast or southern Atlantic coast. Elsewhere, it can be grown in a very large pot to adorn the terrace during the summer season, and brought indoors in winter. The Copernicia hospita is another very beautiful but tender species, best grown in a large pot to protect it from frost in winter.

This palm tree is rather slow to establish. Height varies greatly depending on the species. The Copernicia can reach between 5 to 20 m in height with a spread of 4 to 7 m in the wild or when planted in the ground. When grown in pots, it remains more compact.

This palm features a solitary trunk or stipe. In its natural habitat, it can measure at least 40 cm in diameter. In our climates, it remains quite narrow, light brown-grey in colour, smooth or fibrous and, like all palm trees, marked by the scars of old petioles. On some mature specimens, these foliar remnants create a particularly graphic honeycomb pattern. The very resistant and dense stipe is used for making electricity poles.

Copernicia hospita and alba

At its summit unfolds a crown of large evergreen leaves, keeping the plant attractive all year round. The foliar crown consists of a cluster that may include over 40 leaves or fronds with pleated leaflets like a fan. These are rigid, tough, rounded or perfectly circular, sometimes exceeding 1.50 m in width on the largest specimens. They are attached to the stipe by a thick, long petiole armed with sharp black thorns.

They have a grey-green, almost whitish colour, and a glossy appearance due to the waxy coating that covers them, hence its other name “Wax Palm”. Each leaf has a lifespan of several years.

Flowering is rare in cultivation and only appears in summer on mature specimens. It varies by species and takes the form of inflorescences in panicles or spadices of generally yellow or brown flowers. Some species are monoecious, with hermaphrodite flowers that are both male and female, while others are dioecious, meaning there are male and female plants requiring both genders for the palm to bear fruit.

These small flowers are followed by small, round black fruits measuring 2.5 cm in diameter.

The leaves of the Copernicia prunifera species yield carnauba wax, the hardest of all vegetable waxes. It is, for example, one of the main ingredients in surf wax but is also used in the food, cosmetic and pharmaceutical industries.

Baskets and carnauba wax

Main species and varieties

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Planting Copernicia

Where to Plant It?

Like most palm trees, the Copernicia needs plenty of sunlight. Frost-sensitive, it can only be planted in the ground in mild climates (orange tree zone), as it perishes below -2°C. Plant it in a well-sheltered spot to protect it from winter cold. This is why in colder regions, it must be grown in a large pot and stored away from frost.

In the ground, it grows in any light, compost-rich, well-drained soil that stays moist in summer and rather dry in winter. Adaptable, it will tolerate occasional short periods of drought as well as waterlogged soil in spring and summer. However, in winter, it will fare better in well-drained soil that does not retain water: ensure proper drainage when planting.

Choose the location of your palm tree carefully, as it dislikes being moved once well-rooted due to its brittle and fragile roots.

In mild gardens, it fits perfectly at the centre of a sunny exotic bed, as a standalone feature on a short grass meadow, or in a large container near a swimming pool.

Copernicia prunifera

When to Plant It?

Planting the Copernicia in the garden is done in spring, from March to June after frost, as it needs warmth to establish well.

How to Plant It?

In the Ground

Choose a sunny spot with enough space for it to develop comfortably. If your soil tends to retain water, improve drainage by adding coarse sand or gravel during planting. You can also plant your palm tree on a mound to ensure water drains easily.

• Prepare a large hole, 2 to 3 times the size of the root ball
• Spread a layer of gravel or clay pebbles at the bottom of the planting hole
• Place the palm tree in the centre of the hole
• Fill with a mix of turf, garden soil and sand
• Avoid burying the base of the trunk
• Water thoroughly
• Mulch around the base to keep the soil moist

In a Pot

This palm tree thrives in a large pot, to be placed on the terrace in summer and stored away from frost in winter in less temperate regions.

• Choose a large container with drainage holes, with a capacity of 75 to 100 litres
• Add a drainage layer at the bottom (clay pebbles, gravel, terracotta shards, etc.)
• Prepare a mix of 50% garden soil, 25% standard compost and 25% sand, and partially fill the pot
• Place the palm tree on the mix, without burying the trunk base too deeply
• Fill with the remaining mix, firming well around the root ball
• Water generously

How to care for the Copernicia?

In the Ground

The Copernicia requires little maintenance once well established. During the first few years, it will need regular watering, especially during prolonged dry spells, as it prefers soil that remains cool in summer. Apply mulch around the base to keep its roots cool and reduce the need for watering.

Each year, lightly work some compost into the soil around the base in spring to support growth.

If cold weather is forecast, wrap its fronds in hessian or horticultural fleece. Young plants can be mulched at the base with dead leaves or gravel before the cold sets in to help them through winter.

In spring and summer, you can prune the oldest and damaged leaves back to the trunk. Wear thick gloves as the petiole thorns are unforgiving!

In a Pot

Water approximately once a week during the growing season, allowing the compost to dry out between waterings to prevent root rot.

Feed with organic fertiliser for houseplants once a month from April to September. Wrap its fronds in horticultural fleece and protect the pot with cardboard or bubble wrap if you wish to leave it outside over winter.

If you live in a cooler climate, we recommend protecting it for winter: move the pot to a sheltered, bright room indoors. Reduce watering in winter to once a week and stop fertilising altogether.

Once the risk of frost has passed, you can gradually reintroduce your palm to outdoor conditions, acclimatising it to sunlight.

If roots start emerging from the pot, it’s time to repot. Repot every 3 years or so in spring, transferring your palm to a slightly larger pot while taking care not to damage the fragile roots. For large specimens that are difficult to repot, you can simply replace the top layer of old compost with fresh compost to a depth of about 4 cm. Be cautious of the thorns when tending to your palm!

Diseases and Pests of Copernicia **Common Issues Affecting Copernicia Palms** Copernicia palms, while generally hardy, can occasionally suffer from diseases and parasitic infestations. Here are the most common problems to watch out for: 1. **Fungal Diseases** - **Leaf Spot (Cercospora spp.)**: Causes dark spots on leaves, leading to yellowing and premature drop. - **Root Rot (Phytophthora spp.)**: Overwatering or poor drainage can lead to root decay, wilting, and eventual death. 2. **Parasitic Infestations** - **Scale Insects**: Small, immobile pests that attach to leaves and stems, sucking sap and weakening the plant. - **Spider Mites**: Tiny arachnids causing stippling and webbing on leaves, particularly in dry conditions. **Prevention and Treatment** - Ensure proper watering and drainage to avoid fungal issues. - Apply horticultural oil or insecticidal soap for parasitic control. - Remove and destroy severely infected foliage to prevent spread. By monitoring your Copernicia regularly, you can maintain its health and beauty in your garden. *(Note: Botanical names remain unchanged, while common names follow British English conventions.)*

In our territory, certain pests threaten large palm trees such as the Copernicia. Among them, there are two main ones:

• The Paysandra archon, a large butterfly whose caterpillars infiltrate the heart of the stipe to feed on it, which over time damages the palmate leaves and leads to defoliation.

→ Read more on the subject: “The palm tree butterfly, Paysandisia archon: control and treatment”

• The red palm weevil (Rhynchophorus ferrugineus), whose larvae attack the heart of the stipe and the leaves, which eventually dry out, leading to the certain death of the palm tree. In case of an attack, it is obligatory to report their presence to the town hall. It is a real scourge in the PACA region for palm trees grown in open ground, hence its nickname “palm tree killer”. The larvae of this beetle, originating from Southeast Asia, have been contaminating the entire south of France since 2006.

To learn more, read our advice sheet: How to combat the red palm weevil.

Indoors, red spider mites can threaten the foliage if the atmosphere is too hot, poorly ventilated, and dry: to dislodge them, regularly mist the foliage, as they detest humidity.

Copernicia macroglossa

Propagation

You can propagate Copernicia by sowing in spring, provided it has fruited and you have harvested seeds. This is a lengthy and relatively tedious operation best suited for experienced gardeners. The seeds should be sown warm after soaking. After sowing the seeds on a layer of compost and vermiculite, place your seedlings in a heated greenhouse at 20-25°C. Keep moist until germination, which takes about 2 months. Transplant into buckets and keep warm all winter, protected from frost. Move to the garden or into pots the following spring when the young plants are strong enough.

Pair

Majestic with its slender trunk and graphic fronds, the mere presence of a Copernicia in a garden is often enough to create an exotic atmosphere! It is invaluable for creating a unique, faraway focal point, paired for example with other palm trees like the Yucca, the Phoenix, or other banana plants such as the Musa basjoo.

It will easily be the centrepiece within a bed of tropical-looking plants where the soil retains some coolness in summer. For a beautiful scene with exotic flair, surround it with the warm-toned flowering of Crocosmias, Kniphofias, Eucomis, or Cannas, or with Mediterranean perennials like the Jerusalem Sage or even Agastache ‘Kudos Coral’.

In a more understated composition, in mild climates, plant at its base plants with striking graphic appeal such as Dasylirion, Cordylines, Beschorneria, Phormium, and agaves.

In a pot, it will pair well with mimosas or Strelitzia reginae, or alongside a small palm tree like the Chamaedorea, near a swimming pool, for example, in an exotic-inspired setting.

Copernicia alba alongside Phlomis, banana plants, Crocosmias, and Agastache Kudos Coral