Adenium is a plant used indoors for its appealing blooming and its surprising ornamental qualities.
Adenium key facts:
Caring for it requires careful watering and exposure to avoid disease.
| Name | Adenium obesum |
|---|---|
| Family | Apocynaceae |
| Type | succulent perennial, houseplant |
| Height | 3 to 10 feet (1 to 3 meters) |
| Exposure | full sun |
| Soil | rather rich, very well drained |
| Foliage | drought deciduous, leafless in dry season dormancy |
| Flowering | spring to summer, year-round where warm |
Indoors, this plant requires rather rich soil: best use a good soil mix.
If you plan to plant your desert rose outdoors, wait for spring and choose a sunny spot.
Blend coarse sand, grit or perlite into the potting mix so water drains through fast.
A wide, shallow pot with open drainage holes suits the spreading roots better than a deep one.
Repot into barely larger containers and hold off watering for a few days so torn roots can seal over.
Every part of the plant oozes a toxic milky sap, so wear gloves when repotting.
They don’t need any pruning.
Remove wilted flowers regularly.
The milky sap of a desert rose irritates skin and eyes, so wear gloves and wash your hands after cutting.
Pinch out the growing tips of a single-stemmed plant to make it branch and carry more flowering shoots.
Cut just above a node with clean, sharp secateurs, and let the wound dry in open air before watering again.
Avoid unnecessary cuts into the fleshy caudex, since such wounds rot easily if kept damp; when growers do cut it deliberately to force branching or graft, keep the surface dry and clean.
Adenium flowers on new growth, so shortening a bare, leggy branch pays you back with buds.
Thin out branches that cross or point inwards so light reaches the middle of the plant and the swollen trunk stays on show.
Like all succulent plants, a desert rose only requires very little water, since it stocks it up.
Water thoroughly until it runs from the drainage holes, then leave the mix to dry right through before watering again.
Tip out the saucer after each watering.
A caudex that feels soft or spongy signals too much water, while a slightly wrinkled one means the plant is thirsty.
Leaf drop as temperatures fall is normal dormancy in a desert rose, so resist the urge to water more.
Before reaching for the can, push a wooden skewer down to the bottom of the pot: if it comes out damp or dark, wait.
Use water at room temperature rather than very cold water straight from the tap, as is standard horticultural practice, though evidence that chilling a sun-warmed rootball actually checks growth is limited.
Growers commonly water in the morning because warmth and light speed surface drying during the day, leaving the mix less damp overnight, when prolonged moisture and cool temperatures more readily encourage rot.
Desert roses only require very little care.
Indoors, in an apartment, choose a very sunny location, in direct sunlight for the most part of the day.
You can put it outdoors in summer, but take care not to transfer it immediately to a scorching location. This could dry the plant up and brutal changes can stress it considerably.
Move the pot into dappled shade for a week or two before giving it full outdoor sun, so the leaves harden off instead of scorching.
Bring the plant back inside well before night temperatures approach 50°F (10°C).
Feed lightly during the growing season with a fertiliser low in nitrogen, since too much nitrogen gives leafy growth and few flowers on adenium.
The milky sap of the desert rose is toxic, so wear gloves when handling cut stems and keep the plant away from children and pets.
If you discover cottony white clumps, there is no doubt about it: scale insects. This parasite appears when the air in the room is too dry and the temperature is high.
It may also happen that the desert rose starts rotting when the soil is too moist.
Only water when the soil is dry, and also check that your pot lets excess water drain out away from the roots. Soil must drain very well the pot should have holes at the bottom.
Cold and wet together kill a desert rose faster than either alone.
Adenium obesum is certainly one of the most favored, thanks to its plump, luscious trunk and roots –nearly identical to Ficus ginseng, a famous house bonsai.
Seed-grown adeniums fatten at the base; cutting-grown ones seldom do.
Named double-flowered cultivars are usually grafted onto plain Adenium obesum rootstock, so rub off any shoot that appears below the graft union before it takes over.
Adenium arabicum forms a squat, broad caudex rather than the tall trunk of obesum, which suits a shallow bonsai-style pot.
Every adenium, whatever the flower colour, bleeds a milky sap that is toxic, so wash your hands after handling cut stems.
This magnificent plant is also called baobab rose. It can bloom all year round when it gets older and is well cared for.
