Adenium - Desert Rose: Growing and Care Guide

Botany and description

The Adenium belongs to the Apocynaceae family, a large botanical family that includes often exotic, sometimes toxic, but always fascinating plants. Its genus name, Adenium, originates from the ancient region of Aden in Yemen, where one of the first species was described. In French, it’s commonly called “Desert Rose”, an evocative name that reflects both the beauty of its flowers and its incredible ability to survive in arid environments.

In its natural habitat, the Adenium grows in dry, sunny areas, whether in East Africa or the Arabian Peninsula. It stands out with its swollen trunk, called a caudex, which allows it to store water and withstand long periods of drought. This sculptural aspect, combined with its vibrant flowers in shades of pink, red or white, makes it a highly sought-after houseplant. Its relatively simple care, slow growth and elegant appearance appeal to both succulent enthusiasts and bonsai lovers.

The most commonly cultivated species is Adenium obesum, with its massive caudex and vibrant flowers that somewhat resemble those of the frangipani. But you may also sometimes find hybrids from Adenium arabicum, with an even thicker trunk.

Adenium obesum botanical plate circa 1829, and Adenium obesum socotranum in its natural habitat

The Desert Rose is a succulent plant with a compact, often twisted habit, featuring a silhouette reminiscent of a natural bonsai. Its root system is deep and fleshy, allowing it to store water and survive long periods of drought. Its trunk, thickened at the base, forms a spectacular caudex – swollen and irregular – giving it a unique sculptural appearance. From this trunk emerge relatively short, usually twisted branches, covered with green, smooth and slightly thick leaves that can be evergreen or deciduous depending on growing conditions.

The flowering is one of its main assets, with funnel-shaped flowers in vibrant colours ranging from pale pink to deep red, sometimes edged with white. The flower of Adenium obesum is described as infundibuliform (funnel-shaped) and is typical of the Apocynaceae family. It consists of five petals slightly undulate, arranged in a star around an elongated floral tube. The floral tube, often lighter than the petals, contains stamens fused to the corolla – another distinctive characteristic of Apocynaceae. The pistil is discreet, nestled at the heart of the flower, facilitating pollination by pollinating insects like bees and butterflies.

In favourable climates, it can produce elongated fruits resembling small pods, which release lightweight seeds topped with fine silky hairs once they reach ripeness.

Adenium obesum

Growing Adenium: Pot and Substrate

When to plant an Adenium in a pot?

The best time to plant an Adenium in a pot is in spring, when the plant resumes its growth after the winter dormancy period.

Choosing the pot

The Adenium should be placed in an unglazed terracotta pot, which promotes good evaporation of moisture and reduces the risk of root rot. The size of the pot should be adapted to the caudex: it should not be too deep, as this would retain too much water, but wide enough to allow good root development. Bonsai pots are perfect for this type of plant.

Choosing the substrate

A very well-draining substrate is essential. An ideal mix includes:

• 50% light potting compost,
• 30% coarse sand,
• 20% pumice or perlite to improve drainage.

However, there are ready-to-use composts, perfect for desert roses, such as cactus and succulent composts.

Exposure

Adenium needs intense light to grow and flower well. It should be placed in full sun, near a well-exposed window or outdoors when temperatures are above 15°C. Indoors, a south or west-facing exposure is preferable.

Humidity and ambient temperature

Adenium prefers dry air and does not tolerate excessive humidity. Avoid placing it in humid rooms, such as the bathroom or kitchen.

The Desert Rose loves warmth and dislikes cold. Its ideal growth temperature is between 20 and 35°C, with a preference for warm, sunny days. Below 10°C, its growth slows down and it enters dormancy. In winter, it is crucial to keep it at a minimum temperature of 12 to 15°C to avoid any risk of frost or root rot. If temperatures drop too low, the plant should be brought indoors, in a bright and dry place. The plant dies below 5°C.

Steps for potting

1. Choose a pot with drainage holes at the bottom to ensure good drainage.
2. Place a layer of gravel or clay pebbles at the bottom to prevent water stagnation.
3. Fill the pot with the well-draining substrate, leaving a hollow to accommodate the plant.
4. Position the Adenium, ensuring the base of the caudex is slightly above the substrate to avoid excess moisture.
5. Top up with substrate without packing it down too much, then leave the plant for a few days without watering to allow the roots to heal before gradually resuming irrigation.

Repotting

Repotting should be done every two to three years, always in spring. On this occasion, it is recommended to completely replace the substrate to ensure good root aeration. It is possible to slightly expose the thickened roots to highlight the caudex, but care must be taken not to bury the base of the trunk. After repotting, a temporary halt to watering is necessary to avoid the risk of rot and allow the roots to heal properly.

Growing and Caring for an Adenium

Watering

When the Adenium is in full growth and flowering (spring-summer), water generously, but allow the substrate to dry out completely between waterings. On average, this means watering every 7 to 10 days in summer, depending on heat and exposure.

In winter, when the plant is dormant, it is advisable to reduce watering, or even stop it for a few weeks, and avoid overly humid conditions, especially if temperatures are cool. A light monthly watering may be given if the plant is kept in a warm, dry environment.

Fertilisation

To encourage healthy growth and abundant flowering, Adenium benefits from a balanced fertiliser. During spring and summer, a liquid fertiliser for flowering plants or cacti, rich in phosphorus and potassium, is recommended every 3 to 4 weeks. In autumn and winter, fertilising is unnecessary as the plant slows its activity.

Pruning and Shaping

Pruning is not obligatory, but it helps to stimulate branching and achieve a more balanced habit. It should be done in early spring, before growth resumes. Overlong or uneven branches can be shortened to encourage a more compact structure. Pinching young shoots can also promote new branching. After pruning, allow cuts to dry before watering to prevent infection.

Precautions

Adenium is a toxic plant, particularly its sap, which contains alkaloids that can irritate skin and mucous membranes. It is therefore recommended to wear gloves when pruning and wash hands after handling. Keep it out of reach of children and pets.

→ Also check out our full article: “Adenium or Desert Rose: Seasonal Care Guide“.

Fertilisation will help ensure beautiful flowering

Potential parasitic and disease issues

The most common parasitic pests

• Scale insects: these small white or brown parasitic pests settle on stems, under leaves and sometimes on the caudate, feeding on the sap and weakening the plant. They often leave a sticky deposit (honeydew) which encourages the appearance of sooty mould (a black fungus). They can be removed with cotton wool soaked in 70° alcohol.
• Red spider mites: these tiny mites appear in hot, dry conditions, causing leaves to yellow and fine webs to form. Increasing ambient humidity (not too much, as the desert rose doesn’t like this) and treatment with black soap can eradicate them.
• Aphids: less common, they may appear on young shoots in spring, weakening the plant. A simple jet of water or spray of black soap is usually enough to eliminate them.
• Thrips: these tiny insects suck sap from leaves and flower buds, causing deformations and a silvery appearance on foliage. Treatment with vegetable oil or a natural insecticidal solution can help get rid of them.

Common diseases

• Root and caudate rot: this is the most serious problem for Adenium, caused by overwatering or poorly drained soil. The caudate becomes soft and spongy, and the plant can quickly deteriorate. If the rot is localised, it’s possible to cut away affected parts with a sterilised tool, sprinkle with wood charcoal or cinnamon powder and leave to dry for a few days before replanting in dry soil.
• Stem rot: often due to excessive humidity, it appears as black or brown spots that gradually spread. Pruning affected parts and fungicidal treatment can limit damage.
• Sooty mould: this black fungus develops on honeydew left by scale insects or aphids, covering leaves with a dark layer that blocks photosynthesis. It disappears once the parasitic pests are eliminated, by cleaning leaves with soapy water.

How to prevent these problems?

• Avoid overwatering and always let the soil dry out between waterings.
• Ensure good ventilation by avoiding overly humid and stuffy conditions.
• Place the Adenium in full sun, as strong light strengthens its natural defences.
• Inspect the plant regularly to detect parasitic pests as soon as they appear and act quickly with natural treatments.

To learn more about diseases and parasitic pests of the desert rose, read our full article: Desert rose, Adenium: diseases and parasitic pests.

How to propagate an Adenium?

Adenium can be propagated by sowing and propagation by cuttings, each of these methods having its advantages and disadvantages.

Sowing (preferred method for a beautiful caudex)

Propagation by seeds is the best technique to obtain an Adenium with a well-developed caudex from the start.

Please note: to harvest Adenium seeds, you must wait for the ripe fruits, which are pod-shaped, to dry and begin to open. Once harvested, they should be dried for a few days and sown quickly, as their seed viability decreases rapidly. However, outside of their natural habitat or a dedicated greenhouse (at a pinch!), seed production is extremely rare. Nevertheless, you can purchase them commercially.

• When to sow? Spring and summer are the ideal periods, as warmth promotes germination.
• How to do it?
  1. Soak the seeds in lukewarm water for 6 to 12 hours to speed up germination.
  2. Prepare a very well-draining medium composed of light potting soil, sand and perlite.
  3. Place the seeds on the surface without burying them too deeply and lightly moisten.
  4. Place everything in a warm (25-30°C) and bright location, under a greenhouse or a transparent cloche to retain moisture.
  5. Germination usually occurs within 7 to 14 days.
  6. Once the young plants are well established, gradually space out watering and transplant them into individual pots.

Propagation by cuttings (quicker method, but without a thick caudex)

Propagation by cuttings allows you to quickly obtain a new plant, but it will not have as aesthetically pleasing a caudex as one grown from seeds.

• When to take cuttings? In spring or summer, when the plant is in full growth.
• How to do it?
  1. Take a healthy stem at least 10 cm long, using a clean tool.
  2. Allow the cutting to dry for several days to prevent rotting.
  3. Dip the base in plant hormone powder (optional).
  4. Plant the stem in a very well-draining and slightly moist medium.
  5. Place in a bright and warm location, without excessive moisture.
  6. Rooting usually takes 4 to 6 weeks.

How to showcase a desert rose?

With its sculptural caudex and striking flowering, the Adenium fits perfectly into bright interiors with minimalist, exotic or bohemian styles. It will thrive particularly well in a modern and sleek setting, where its graphic shapes will be highlighted, or in a tropical-inspired interior, paired with other arid plants like cacti and succulents.

Which pot to choose?

To enhance its unique appearance, it is best placed in:

• A raw terracotta pot, which recalls its natural medium and promotes good drainage.
• A stylish matte ceramic pot, in neutral tones (white, beige, grey) for an elegant and contemporary look.
• A hanging or elevated pot, which will showcase its caudate base and give an airy effect to the composition.
• A concrete pot, ideal for an industrial and minimalist decor.

What about in a terrarium?

The Adenium is not suited to closed terrariums, as it requires dry air and excellent ventilation. However, it can be placed in an open, desert-style terrarium with sand, stones and other succulents like haworthias or lithops. In this case, it is essential that the substrate is extremely well-draining and that watering remains very moderate.