Ever the subject of debate is the genus Adenium of up to 11 species. Many experts insist that most of these species are all subspecies of Adenium obesum.
One of these is Adenium swazicum (a-DEE-nee-um SWAZ-ih-kum), now known as Adenium Boehmianum or the impala lily, which calls its natural habitat Swaziland, Somalia, Yemen and parts of South Africa.
Expansion of sugarcane plantations has critically endangered this perennial species in its native habitat. But is well-preserved as a popular houseplant and bonsai plant.
All Adenium varieties belong to the Apocynaceae family. They gained the common nickname of desert rose due to their visual similarities to plumeria.
Adenium swazicum has many common names, which all have a similar origin:
- Impala Lily
- Sisila-sempala (SiSwati)
- Summer impala lily
- Swazi lily
- Swazi-lelie (Africaans)
The SiSwati name translates to “tail of impala,” as the leaves cluster in a way that resembles the tail of this common animal.
Desert Rose Care
Size and Growth
These slow-growing, long-lived plants can be pretty hardy once established. But they won’t develop an underground tuber until after their first 2 years of life.
They grow to about 24″ inches tall and wide, with a more fragile stem and branches than many of their siblings.
The caudex becomes less visible with age, and the sparse branches droop like a weeping willow.
The long leaves are succulent and grow in clusters at the ends of the branches.
A velvety grey-green, each leaf is thin and tapered at both ends or thicker at the tip.
Younger leaves may be hairy on the underside but bald as they age.
Meanwhile, it’s not uncommon for the leaves to fold along the midrib.
Flowering and Fragrance
Blooms appear throughout the summer, usually pink but sometimes white or reddish pink with a deeper red center.
In their native habitat, hawkmoths pollinate the flowers at dusk. They rarely attract other pollinators during the day.
Pollinated flowers give way to tiny, horn-shaped seeds that float on a tuft of hair.
These seeds will take root when placed into adequate soil conditions.
Light and Temperature
Bright, indirect light is ideal for this plant, as direct sunlight can lead to scalding of the caudex.
Dappled light also works well outdoors, and it will tolerate partial shade.
The plant won’t flower if it doesn’t receive adequate lighting. Make sure it gets some full sun in the morning if you put it in a spot that has partial afternoon shade.
The risk of root rot is high, so your adenium will fare best in lower humidity.
You can plant impala lily outdoors in USDA hardiness zones 10a to 11b, but they can’t handle freezing temperatures.
Indoors, aim for an ambient temperature of 75° – 95° degrees Fahrenheit.
The plant will go dormant and may display leaf drop in temperatures between 35° – 55° degrees Fahrenheit.
Temperatures below 32° degrees Fahrenheit can kill the plant, especially if the soil isn’t dry.
Watering and Feeding
It can be challenging to tell when the Desert Rose plant needs watering. Adeniums can handle periods of drought and generally doesn’t use the top third of their soil.
When the soil feels dry below that level, give your desert rose a slow, thorough watering with room temperature distilled water or rainwater. Stop when the excess begins to seep from the pot’s drainage holes.
It’s usually best to water in the morning and to avoid splashing, as water on the trunk can lead to scorching in the sunlight.
Avoid watering in winter, as this is the plant’s standard dormant period, and wet soil can lead to frost damage.
Choose a low-dose liquid or slow-release fertilizer that has a lower nitrogen content. More on Desert Rose Fertilizer.
Dilute and apply according to the package instructions weekly during the summer.
Soil Potting Mix and Transplanting
Impala lily likes sandy soils and needs a loose medium with good drainage.
A 50/50 mix of perlite and either sand or mulch works well.
You may also choose an orchid or succulent mix, adding perlite to ensure it stays loose.
These plants don’t use the top third of their soil for more than stability. Making this a layer of mulch, orchid bark, or other organic material will help keep the plant well-fed.
It’s pretty rare when this plant needs repotting. Do so every 2 to 3 years to refresh the Adenium soil or if you see roots beginning to creep through the drainage holes.
Grooming and Maintenance
You generally won’t have to worry about grooming your impala lily outside of pruning away damaged or diseased leaves.
Adenium Swazicum Propagation
This particular adenium is easy to propagate.
The techniques to pick from include leaf cuttings, offshoots, seeds, and stem cuttings.
Related: Starting Desert Rose From Seeds
Adenium Pests or Diseases
This plant is drought resistant and has a moderate tolerance to salt and animals.
Its main enemy is root rot, which can quickly kill the plant.
Common insects include infestations of aphids, mealybugs, and high susceptibility to spider mites.
The sap of this plant is highly poisonous.
Adenium Swazicum Uses
In the garden, this species of desert rose is commonly used in rockeries, where its flowers provide plenty of attraction.
It’s also a popular container plant.
The highly poisonous sap of this plant was traditionally used to tip arrowheads for hunting.
Properly diluted, it is a traditional folk remedy for heart failure and various skin diseases.
The stem is often powdered and used topically on livestock to kill parasites.
Other Popular Adeniums include:
- Adenium Arabicum
- Adenium Multiflorum
- Adenium Somalense
- Adenium Crispum